Log Message:
libatomic_ops: updated to 7.6.2

Changes:
Allow to alter DEFAULT/MAX_NTHREADS values in test_malloc/stack
Allow to select almost-non-blocking stack implementation explicitly
Annotate AO_malloc with 'alloc_size' and 'malloc' attributes
Avoid misleading 'AO_t undefined' error if wrong atomic_ops.h included
Define AO_TS_SET to 1 (true) if GCC atomic_test_and_set is used
Disable workaround in stack_pop_acquire that was needed for ancient Clang
Do not define AO_GCC_FORCE_HAVE_CAS for Clang 3.8+ (Aarch64)
Do not disallow to define double_load using built-in atomics (Aarch64)
Do not expose AO_GCC_FORCE_HAVE_CAS macro to client code (GCC)
Do not install documentation if configure --disable-docs (new option)
Do not produce .tar.bz2 distribution file (configure)
Eliminate '-pedantic is not an option that controls warnings' GCC message
Eliminate data race in cons() of test_malloc
Eliminate GCC-5 ASan global-buffer-overflow false positive for AO_stack_bl
Fill in allocated memory with values depending on thread id (test_malloc)
Fix 'bad register name %sil' assembler error (GCC-4.4/x86)
Fix 'unknown attribute no_sanitize' compiler warning for GCC
Fix AO_malloc for sizes near CHUNK_SIZE
Fix memory leak in test_malloc
Fix test failures for Clang-3.8 and older (Aarch64)
Fix test_stack failure if AO_PREFER_BUILTIN_ATOMICS (GCC/Aarch64)
Fix typo in AO_REAL_NEXT_PTR comment
Increase the default number of threads to 16 in test_malloc/stack
Mark unallocated/freed memory as inaccessible using ASan functionality
New macro (DONT_USE_MMAP) to support testing as if mmap() is unavailable
New macro to select stack implementation based on CAS-double
Place no_sanitize attributes in a GCC-compliant way
Prevent too long run of test_atomic_generalized (especially with TSan)
Simplify '#if' expressions in gcc/x86.h (code refactoring)
Test smallest allocation of large type (test_malloc)
Use __builtin_expect in atomic_ops_malloc
Use built-in atomics for load/store/CAS for Clang by default (Aarch64)
Use double-word atomic intrinsics for recent Clang versions (gcc/x86.h)
Use GCC atomic intrinsics for Hexagon (clang 3.9+)
Use generalized double-wide load/store if AO_PREFER_GENERALIZED (Aarch64)
Workaround 'unused result' code defects in atomic_ops.c, list_atomic
Workaround Thread Sanitizer (TSan) false positive warnings
Also, includes 7.4.8 changes