Log Message:
Update MoarVM to 2017.06. Bump API_DEPENDS too, as functions have been
removed.

2017.06

- Make coerce_s_n work more like the Perl 6 Str.Num method
- Eliminate socket string I/O
- Re-implement synchronous sockets without using libuv, enabling them to
  be passed between threads
- Add ability to get port from already bind-ed socket
- Add cpucores op to get the number of CPU cores
- Fix inconsistency in decode stream take bytes API, so it returns null
  if that number of bytes is not available
- Fix memory leak in syncpipe
- Removed unsed header file in threads.c
- Remove unused args to bind_stdio_handle
- Remove char-level I/O ops and the functions they called
- Remove char-level I/O from synchronous I/O vtables
- Remove unused encoding option in dir handle
- Re-implement print/say debug output ops to encode and then use binary
  I/O
- Eliminate use of libuv in synchronous file handles
- Switch standard handles to use the new synchronous file handle code,
  which means they can now be safely used from multiple threads also
- Remove unused ->filename slot of syncfile
- Debugging aid for introspecting P6opaque objects
- Support merge_bytes in async proc ops, for reading STDOUT and STDERR
  together
- Support binding handles to file descriptors in async procs
- Fix off-by-one in profiler node GC
- Add string eqat/index ignorecase+ignoremark functions
- Add new eqaticim_s and indexicim_s ops ignorecase+ignoremark
- Use norm instead of n for the normalizer variable
- Add improved support for GCB=Prepend
- Improve Regional Indicators support during normalization
- Serialize a Decoder REPR object into null, so incidental file handle
  serialization in Perl 6 does not blow up
- Improve named argument optimization, so we can specialize and throw
  out instructions in more cases
- JIT decodertakeline
- Fix missed opportunity to run JITted code
- Have inline log note what couldn't inline also
- Remove successor when optional named argument is passed, so default
  code can be eliminated
- Flag writers that die when a basic block is eliminated, and disregard
  them in PHI node analysis, provide more precise type information
- Make a basic block elimination pre-pass before the main optimization
  work
- Set dead writer when deleting instructions also, to further aid PHI
  merges
- Track which basic blocks are part of a jump list
- Delete pointless goto instructions (those at the end of a basic block
  that simply go to the next block)
- Remove bad Windows quoting option async proc code
- Actually log inlines to stderr as the comment up top claims
- Make find_separator only look at the last chars, which is far cheaper
- Add help text for environment variables to Configure
- Move NFG initialization into nfg.c
- Cache CRLF grapheme value
- Cache maximum separator length, to save recomputing it for every line
  that is read
- Cache a list of final separator graphemes, for faster stopper
  detection in streaming decoders
- Introduce a max final grapheme codepoint filter, for faster stopper
  detection in streaming decoders
- Add a UTF-8 decoding fast-path that doesn't need to go through the
  full normalizer
- Keep last freed chars buffer handy for re-use in streaming decoder
- Make a smarter guess at decode result buffer size in streaming decoder
- Don't copy when we can steal decoder output, saving a memory copy in
  most line reading operations
- Various micro-optimizations to UTF-8 decoding fast path
- Fix newline translation in various encoding's streaming decoder

2017.05

- Mark profiler call graphs iteratively instead of recursively
- Keep around line number annotations in spesh, for more accurate source
  position information for coverage data in specialized code
- Introduce "telemeh", a high-precision-time low-impact logger
- Fix error reporting in chdir
- Fix memory leak on error in chdir
- Travis: readlink doesn't have `-f` on MacOS so make our own solution
- Fix bug in index ignorecase and equal at ignorecase
- Fix all known remaining bugs in indexic and eqatic
- Zero slot when popping a VMArray, to avoid junk reads if it grows
  again later
- Add can_fit_into_8bit funct, put logic used many places into one
  function
- Use -1 instead of 0 when long right-shifting negative smallints
- Remove workaround for tommath issue #56, which is now fixed upstream
- Don't crash on reading a closed dir handle
- Remove deprecated async string I/O ops

2017.04

- Shorten the nursery when creating large bigints, to bring GC forward
  and resolve excessive memory use
- Use correct format for repeat/concat errors
- Fix bug in indexic_s if expanding codepoint is the last codepoint
- Special case "\r\n" in MVM_nfg_is_concat_stable for performance
  reasons
- Further optimize MVM_nfg_is_concat_stable to speed up concatenation
- Do not set use rpath if installing into proper system locations
- Optimize passes_quickcheck_and_zero_ccc to be much faster
- Give this_repr constants more meaningful names to aid debugging
- Streamline MVM_bigint_radix and MVM_radix for Nd Unicode #'s
- Fix case-insensitive string compare bug when synthetics are in the
  haystack
- Improve description for "should eventually be unreachable" error
- Correctly detect and handle overflow in mp_get_int64
- Split into mp_get_int64 and mp_get_uint64
- Only allocate and normalize for cp's that require it in
  MVM_string_chr, and short-circuit Unicode property test for codepoints
below 0x300
- Provide a better error when failing to encode surrogates in UTF-8
- Add a cast to suppress a compiler warning in strings/ops.c
- Factor out code from equal_at_ignore_case for use in index_ignore_case
  also
- Use both hex and decimal for UTF8 encoding error messages
- Add parentheses in various places to suppress compiler warnings
- Use PRIu64 in fprintf's to fix compiler warning about incorrect types
- Add a check that introspection->is_tty is not NULL, avoiding a crash
- Mention debug_name in errors about uncomposed repr
- Add new --coverage option for Configure.pl
- First prototype of a per-line coverage reporter, enabled by setting
  MVM_COVERAGE_LOG
- Cope with a native type with no nativesize, but signedness
- Remove two functions in normalize.c that have been superseded
- Give collapse_strands a 5.4% speed boost under some workloads
- Add MVM_string_graphs_nocheck funct, use it in places we previously
  already checked
- Have a two-part loop in collapse strands to make loop tighter when
  possible
- Implement serialize/deserialize in VMHash REPR
- Use memmem in string index. Uses Knuth-Morris-Pratt on glibc, and adds
  the FreeBSD memmem.c for use on Windows
- Fix a join NFG bug when there was an empty string and an empty
  seperator
- Reorder MVMStaticFrameBody to save 16 bytes according to pahole;
  similarly save 16 bytes in MVMCompUnitBody, 24 bytes in MVMJitCode, 8
bytes in MVMIOSyncStreamData, SerializationRoot and SerializationReader
- Remove arbitrary and small length range check for reading bytes from a
  file
- Remove unused defines in threadcontext.h
- Greatly reduce contention in the fixed-size allocator for
  multi-threaded programs, giving up to 40% speedup in some cases
- Add continuous coverage analysis to Travis builds, along with other
  Travis improvements
- Mark thread GC blocked when doing synchronous writes
- Add missing MVMROOT when reading bytes, which could result in
  occasional data loss

2017.03

- Fix some missing variable initializations
- Set effective_handlers in context-only frame
- Streamline code in hash computation, hopefully fixing a Coverity
  warning
- Detect and throw on over-size array
- Put in a limit for codepoints in a grapheme, to avoid various
  overflows
- Fix a missing NULL check at end of profiling
- Panic when a new thread context can't create an uv_loop
- Better handling of out of memory when creating a thread
- Another attempt at silencing the pthread_yield warnings
- Missing GC block marking in event loop starting, fixing a deadlock
- Fix CArray marshalling of type objects
- Provide a way to put Decoder in nl-translate mode
- Ensure Decoder REPR never sees concurrent use
- Debug option to detect concurrent VMArray use
- Encode strings as UTF-8 in MVM_unicode_string_from_name
- Reword exception message for read() outside original thread
- Check that results of repeat/concat fit in an MVMString
- Fix div_i JIT round to negative infinity
- Ignore SIGPIPE by default
- Only start readers if a process spawned OK
- Remove deprecated char-mode async proc reading
- Signal error to stdout/stderr on spawn failure
- Do gen2 sweep before letting stolen threads go, fixing occasional
  SEGVs
- Turn libtommath dependency into a submodule, use a MoarVM fork
- Update libtommath fork to have expmod hang fix
- Change MVM_string_equal_at_ignore_case to use fc
- Fix MVM_string_equal_at_ignore_case when folding the haystack changes
  length
- Mention debug name and REPR name in "requires obj with repr X" errors
- Remove unneeded variable in MVM_string_index
- Add MVM_string_index_ignore_case function and indexic_s op
- A range of improvements to the MoarVM GDB plug-in

2017.02

- Fix format strings that warn during compile
- Implement missing cleanup of async task handles, fixing a memory leak
- Make Unicode sequence and codepoint name lookup case-insensitive
- Add Unicode sequences from NamedSequences.txt in the Unicode database
- Remove second declaration of MVM_frame_destroy
- JIT MVM_radix()
- Make radix and radix_I 50% faster with Unicode Nd
- Add East_Asian_Width prop
- Fix memory leaks in synchronous sockets
- Fix crashes in socket connect error handling
- Don't leak memory in STable repossession
- Missing MVMROOT around a lock acquisition
- Refuse to form an NFA with a zeroed to-state
- Add data section for JIT code, and use it for extop 'fake' registers
- Correct typo in NFG trie node struct name
- Fix overflow in div_i op
- Implement support for synthetic graphemes in
  MVM_unicode_string_compare
- Implement configurable collation_mode for MVM_unicode_string_compare
- Use LDFLAGS in ld invocations
- On Windows, create UTF-8 encoded argv upon program entry
- On Windows, populate environment hash from Unicode environment
- Some additional heuristics to cut down on cross-thread write log
  output
- Fix abs_n op for negative zeros
- Sort out semantics of closed async sockets
- Fix overflow on 32-bit systems in is_full_collection()
- Rename MVMArray file and constant to VMArray
- Remove bogus indication that MoarVM builds on `cygwin`
- Use utf8 for unicode_db files
- Fix invalid read when GC was triggered in the string repeat op
- Don't call MVM_string_graphs twice in indexing op, plus cleanup