[compiler-rt] [win/asan] Recognize mov QWORD PTR [rip + X], reg (PR #117335)

[via llvm-commits]

zmodem wrote:

Yes, it's somewhat ironic that we're playing whack-a-mole with these instruction encoding, while at the same time LLVM has them all in its .td files and also includes a working disassembler.

So it definitely seems like we could do something more rigorous here. On the other hand, the code was originally intended to just handle a few common function prologues. Maybe we don't want to get too fancy.

Conversely, @rnk has often suggested that we should perhaps move away from win/asan doing this binary patching at all, and instead only do interception at the DLL boundaries. For statically linked symbols, it seems better to link in the symbols we want from the start.

For now, I'll go ahead and merge this one since it's just a small addition to what we currently have.

https://github.com/llvm/llvm-project/pull/117335