[compiler-rt] asan_static x86-64: Support 64-bit ASAN_SHADOW_OFFSET_CONST (PR #75748)

[Fangrui Song via llvm-commits]

MaskRay wrote:

> So unless I'm understanding it incorrectly, this commit achieved the inverse of what it was supposed to do? Note the assembler complaining here is clang's own internal one... :)

The patch is insufficient. There is another place in `ASAN_MEMORY_ACCESS_CHECK_ADD` that is just resolved by 
https://github.com/llvm/llvm-project/pull/76185


https://github.com/llvm/llvm-project/pull/75748