Duplicate assembly macros

[am11]

In CoreRT, we copied a few assembly macros from CoreCLR repo. Those macros were later modified in coreclr then in runtime repos. Now that NativeAOT and PAL code exist in the same repo, is it feasible to deduplicate that code?

/runtime $ git ls-files ':/src/coreclr/pal/*unixasmmacros*.inc'
src/coreclr/pal/inc/unixasmmacros.inc
src/coreclr/pal/inc/unixasmmacrosamd64.inc
src/coreclr/pal/inc/unixasmmacrosarm.inc
src/coreclr/pal/inc/unixasmmacrosarm64.inc
src/coreclr/pal/inc/unixasmmacross390x.inc
src/coreclr/pal/inc/unixasmmacrosx86.inc

# vs.

/runtime $ git ls-files ':/src/coreclr/nativeaot/*unixasmmacros*.inc'
src/coreclr/nativeaot/Runtime/unix/unixasmmacros.inc
src/coreclr/nativeaot/Runtime/unix/unixasmmacrosamd64.inc
src/coreclr/nativeaot/Runtime/unix/unixasmmacrosarm.inc
src/coreclr/nativeaot/Runtime/unix/unixasmmacrosarm64.inc
src/coreclr/nativeaot/Runtime/unix/unixasmmacrosx86.inc

cc @MichalStrehovsky, @jkotas, @janvorli

[am11]

cc @directhex (regarding #62594 (comment)), for some reason the outerloop armv6 failure is caused by /pal/ variant

runtime/src/coreclr/pal/inc/unixasmmacrosarm.inc

Line 265 in a5cf724

tst r0, #7

but not the nativeaot one:

runtime/src/coreclr/nativeaot/Runtime/unix/unixasmmacrosarm.inc

Line 185 in a5cf724

tst r0, #7

(although both components are bulilding; maybe it's unreachable code 🤔)

[MichalStrehovsky]

It would definitely be nice to deduplicate.

My only concern is that we currently have zero testing for NativeAOT ARM64 (outside of just building it), so I would rather not make big changes to ARM64 files right now. ARM64 testing is on my TODO list for the coming weeks.

but not the nativeaot one:

NativeAOT is only building on ARM64 and x64:

runtime/src/coreclr/CMakeLists.txt

Lines 137 to 142 in a5cf724

	if(NOT CLR_CROSS_COMPONENTS_BUILD)
	# NativeAOT only buildable for a subset of CoreCLR-supported configurations
	if((CLR_CMAKE_HOST_LINUX OR CLR_CMAKE_HOST_OSX OR CLR_CMAKE_HOST_WIN32) AND (CLR_CMAKE_HOST_ARCH_ARM64 OR CLR_CMAKE_HOST_ARCH_AMD64) AND NOT (CLR_CMAKE_HOST_OSX AND CLR_CMAKE_HOST_ARCH_ARM64))
	add_subdirectory(nativeaot)
	endif()
	endif(NOT CLR_CROSS_COMPONENTS_BUILD)

It might be buildable on ARM32, but this was scoped down to what we really need in the initial move from runtimelab.