4.2.1

Bug fixes:

• Fix bootstrapping issues for configurations that require allocation during tsd initialization (e.g. --disable-tls). (@cferris1000, @jasone)
• Fix gettimeofday() version of nstime_update(). (@ronawho)
• Fix Valgrind regressions in calloc() and chunk_alloc_wrapper(). (@ronawho)
• Fix potential VM map fragmentation regression. (@jasone)
• Fix opt_zero-triggered in-place huge reallocation zeroing. (@jasone)
• Fix heap profiling context leaks in reallocation edge cases. (@jasone)