Log Message:
verilator: Update to 4.100

Changelog:
* Verilator 4.100 2020-09-07

**    C++11 or newer compilers are now required.

**    SystemC 2.3.0 or newer (SYSTEMC_VERSION >= 20111121) is now required.

**    Support hierarchical Verilation (#2206). [Yutetsu TAKATSUKASA]

****  Support (with limitations) class extern, class extends, virtual class.

****  Support $urandom, $urandom_range without stability.

****  Fix false DECLFILENAME on black-boxed modules (#2430). [Philipp Wagner]

****  Fix naming of "id : begin" blocks.

****  Fix class constructor error on assignments to const.

****  Fix splitting eval functions with --output-split-cfuncs (#2368). [Geza Lore]

****  Fix queues as class members (#2525). [nanduraj1]

****  Add support for assume property. [Peter Monsson]

* Verilator 4.040 2020-08-15

**    Version 4.040 is planned to be the final version that will
      support pre-C++11 compilers. Please move to C++11 or newer compilers.

***   Fix arrayed interfaces, broke in 4.038 (#2468). [Josh Redford]

****  Support $stable, $rose and $fell.  (#2148) (#2501) [Peter Monsson]

****  Support simple function localparams (#2461). [James Hanlon]

****  Miscellaneous parsing error changes towards UVM support.

****  Fix arrayed interfaces (#2469).  [Josh Redford]

****  Fix protect lib VCS warning. (#2479) [Julien Margetts]

****  Fix combining different-width parameters (#2484). [abirkmanis]

****  Fix protect-lib without sequential logic (#2492). [Yutetsu TAKATSUKASA]

****  Fix V3Unknown from running with flat XML output (#2494). [James Hanlon]

****  Fix non-32 bit conversion to float (#2495). [dsvf]

****  Fix casting non-self-determined subexpressions (#2493). [phantom-killua]

****  Fix SystemC net names (#2500). [Edgar E. Iglesias]

****  Fix build with Bison 3.7 and newer (#2505). [Rupert Swarbrick]

****  Fix slice of unpacked array (#2506) (#2507). [Yutetsu TAKATSUKASA]

* Verilator 4.038 2020-07-11

**    Versions 4.038 and 4.040 are planned to be the final versions that will
      support pre-C++11 compilers. Please move to C++11 or newer compilers.

***   Support VPI access to parameters and localparam. [Ludwig Rogiers]

***   Support parsing (not elaboration, yet) of UVM.

****  Add new UNSUPPORTED error code to replace most previous Unsupported: messages.

****  With --bbox-unsup continue parsing on many (not all) UVM constructs.

****  Support for-loop increments with commas.

****  Support $swrite with arbitrary arguments.

****  Support $writememb (#2450). [Fan Shupei]

****  Fix OS X, Free BSD, and -m32 portability issues. [Geza Lore]

****  Fix to flush FST trace on termination due to $stop or assertion failure.

****  Fix part select error when multipling by power-of-two (#2413). [Conor \ 
McCullough]

****  Fix division exception (#2460) [Kuoping Hsu]

* Verilator 4.036 2020-06-06

**    OPT_FAST is now -Os by default. See the BENCHMARKING & OPTIMIZATION part
      of the manual if you experience issues with compilation speed.

***   Configure now enables SystemC if it is installed as a system headers,
      e.g. with 'apt-get install systemc-dev'.

***   Add --waiver-output flag that writes a verilator config file (.vlt) with
      waivers to the warnings emitted during a Verilator run.

***   Support verilator_coverage --write-info for lcov HTML reports.
      Line Coverage now tracks all statement lines, not just branch lines.

***   --output-split is now on by default. VM_PARALLEL_BUILDS is set by
      default iff the --output-split caused an actual file split to occur.
      --output-split-cfuncs and --output-split-ctrace now default to the
      value of --output-split. These changes should improve build times of
      medium and large designs with default options. User makefiles may
      require changes.

***   The run-time library is now compiled with -Os by default. (#2369, #2373)

****  Support multi channel descriptor I/O (#2190) [Stephen Henry]

****  Support $countbits. (#2287) [Yossi Nivin]

****  Support $isunbounded and parameter $. (#2104)

****  Support unpacked array .sum and .product.

****  Support prefix/postfix increment/decrement. (#2223) [Maciej Sobkowski]

****  Fix FST tracing of little bit endian signals. [Geza Lore]

****  Fix +: and -: on unpacked arrays. (#2304) [engr248]

****  Fix $isunknown with constant Z's.

****  Fix queues and dynamic array wide ops. (#2352) [Vassilis Papaefstathiou]

* Verilator 4.034 2020-05-03

**    Add simplistic class support with many restrictions, see manual. (#377)

**    Support IEEE time units and time precisions. (#234)
      Includes `timescale, $printtimescale, $timeformat.
      VL_TIME_MULTIPLIER, VL_TIME_PRECISION, VL_TIME_UNIT have been removed
      and the time precision must now match the SystemC time precision. To
      get closer behavior to older versions, use e.g. --timescale-override
      "1ps/1ps".

**    Add --build to call make automatically. (#2249) [Yutetsu TAKATSUKASA]

**    Configuring with ccache present now defaults to using it; see OBJCACHE.

**    Fix DPI import/export to be standard compliant. (#2236) [Geza Lore]

**    Add --trace-threads for general multithreaded tracing. (#2269) [Geza Lore]

***   Add --flatten for use with --xml-only. (#2270) [James Hanlon]

****  Greatly improve FST/VCD dump performance (#2244) (#2246) (#2250) (#2257) \ 
[Geza Lore]

****  Support $ferror, and $fflush without arguments. (#1638)

****  Support event data type (with some restrictions).

****  Support $root. (#2150) [Keyi Zhang]

****  Add error if use SystemC 2.2 and earlier (pre-2011) as is deprecated.

****  Fix build of fast path tracing code to use OPT_FAST. (#2245) [Geza Lore]

****  Fix arrayed instances connecting to slices. (#2263) [Don/engr248]

****  Fix error on unpacked connecting to packed. (#2288) [Joseph Shaker]

****  Fix logical not optimization with empty begin. (#2291) [Baltazar Ortiz]

****  Fix reduction OR on wide data, broke in v4.026. (#2300) [Jack Koenig]

****  Fix clock enables with bit-extends. (#2299) [Marco Widmer]

****  Fix MacOs Homebrew by removing default LIBS. (#2298) [Ryan Clarke]

* Verilator 4.032 2020-04-04

***   Add column numbers to errors and warnings.

***   Add GCC 9-style line number prefix when showing source text for errors.

***   Add setting VM_PARALLEL_BUILDS=1 when using --output-split. (#2185)

***   Change --quiet-exit to also suppress 'Exiting due to N errors'.

****  Suppress REALCVT for whole real numbers.

****  Support split_var in vlt files. (#2219) [Marco Widmer]

****  Fix parameter type redeclaring a type. (#2195) [hdzhangdoc]

****  Fix VCD open with empty filename. (#2198) [Julius Baxter]

****  Fix packages as enum base types. (#2202) [Driss Hafdi]

****  Fix duplicate typedefs in generate for. (#2205) [hdzhangdoc]

****  Fix MinW portability. (#2114) [Sean Cross]

****  Fix assertions with unique case inside. (#2199) [hdzhangdoc]

****  Fix implicit conversion of floats to wide integers.