[libunwind] Clean up __arm64__
`__aarch64__` is defined for the target (since the beginning of arm64 support: clang 3.5).
`__arm64__` is only defined for the Darwin OS on AArch64.
`defined(__aarch64__) || defined(__arm64__)` can be simplied as `defined(__aarch64__)`
Darwin AArch64 uses %% as the assembly separator (see AArch64MCAsmInfo.cpp).
Make the intention explicit in src/assembly.h
With this change, the libunwind code base has no reference of `__arm64__`/`__arm64`.
Reviewed By: #libunwind, ldionne, mstorsjo
Differential Revision: https://reviews.llvm.org/D77829
Cr-Mirrored-From: https://chromium.googlesource.com/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: f3d460ce5874e4dd12b8cf8b227de4cec43a685c
5 files changed
