remove i64Math_add
add compiler-rt files for 64-bit math
add handwritten asm i64Subtract
add i64 testing
add more i64Subtract testing
asmify ctlz/cttz
add option to move elements from post into before the asm block
use compiled compiler-rt code for i64 multiplication
use compiled i64 div and rem
Remove unused file.
Add musl wchar function implementations.
Use the wchar functions from musl.