This commit implements all the arm64 instruction encodings necessary
for our JIT compiler and replaces the golang-asm assembler with our
handmade assembler on arm64 platform. Notably, this allows us to do
concurrent compilations.
This closes#233 combined with #406.
Signed-off-by: Takeshi Yoneda <takeshi@tetrate.io>
Co-authored-by: Adrian Cole <adrian@tetrate.io>