Fix some typos/grammar in registerizeHarder comments
Fix input-register-conflict checking in native registerizeHarder
Merge pull request #3080 from rfk/rfk/fix-native-registerize-harder

Fix input-register-conflict checking in native registerizeHarder
Fix link to hello_world_file.cpp in tutorial. Closes #3077.
update cashew for some hashing optimizations
Add SIMD mul and shift operators to the list.
optimize conf filling in native optimizer
reserve room for conf vars in native optimizer
comment
Migrate to using musl 1.0.3 math functions to avoid jumping out of asm.js path and generating garbage.
Add musl fenv.c needed by musl math functions.
Add symbol __fpclassifyd as an alias to __fpclassify to satisfy test_python.
Merge pull request #2905 from juj/musl_mathfuncs

Musl mathfuncs
update cashew
Fix up sincos, sincosf and sincosl to call to browser sin and cos functions to fix missing symbols in libc build, and to give better performance than the musl provided ones.
make other.test_js_optimizer:registerizeHarder invariant to reorderings of sensitive variables
enable native optimizer by default
disable slow2asm legacy testing, and add a testing mode for the non-native js optimizer
remove more useless subnodes in native optimizer
make other.test_emterpretify more tolerant of native optimizer variability