[mono][jit] arm64 neon opcodes

[jandupej]

This adds macros for emitting arm64/neon opcodes to be used by mini JIT. FP16 and scalar are omitted for now. #80788

[vargaz]

There is a codegen-test.c which can be used to test these, the idea is to add codegen macros to it, then run the output through an assembler, and disassembler, then look at it manually, or compare it with a file:

test-codegen:
	$(CC) $(CFLAGS) -I../../.. -I../../eglib/ ../../eglib/.libs/libeglib.a -o codegen-test codegen-test.c
	./codegen-test > tmp.s
	$(CC) $(CFLAGS) -c -o tmp.o tmp.s
	objdump -d --triple=arm64e tmp.o

[jandupej]

There is a codegen-test.c which can be used to test these, the idea is to add codegen macros to it, then run the output through an assembler, and disassembler, then look at it manually, or compare it with a file:

test-codegen:
	$(CC) $(CFLAGS) -I../../.. -I../../eglib/ ../../eglib/.libs/libeglib.a -o codegen-test codegen-test.c
	./codegen-test > tmp.s
	$(CC) $(CFLAGS) -c -o tmp.o tmp.s
	objdump -d --triple=arm64e tmp.o

To be implemented in 81420.