fix glIsTexture from throwing a warning on null-ified textures, and add testing
docs for file packager
Add GC support for GC_MALLOC_UNCOLLECTABLE.
Add myself to AUTHORS.
Add support for GC_REALLOC().
Don't corrupt GC.totalAllocations.
Support GC_get_heap_size().
Add _realloc to EXPORTED_FUNCTIONS.
Move some definitions to sys/features.

This moves some feature flags to sys/features.h where they belong
and gives them the same values that are established in the settings
file.

Fixes #812.
Variables live across a setjmp/lj must be volatile.

According to http://pubs.opengroup.org/onlinepubs/7908799/xsh/setjmp.html
among other places, the 'int x' here should be volatile so that it has
the correct value. Otherwise, the behavior will be indeterminate.
semi polyfill for Math.imul
do not build musl memcpy
fix memcpy
update relooper tests
always use labels in multiple blocks; emit no more one-time loops but rather labeled ifs
eliminate into labels
fix reps printing in benchmarks
do not run unnecessary optimizeShiftsAggressive+eliminate steps in asm mode, it is pointless and just wastes compilation time
improve eliminator test flexibility, fixes #822
Fix test_llvmswitch to be valid C++11 code. Using an unsigned type would cause an error: case value evaluates to 4294967281, which cannot be narrowed to type 'int' [-Wc++11-narrowing] when compiled as C++11.