[compiler-rt] [profile] Implement a non-mmap path when reading profile files from a non-local filesystem (PR #131177)

[Wael Yehia via llvm-commits]

w2yehia wrote:

@ahatanak @aeubanks Thanks for notifying and reverting.
I don't have a mac but got a colleague to try out a fix for me. I also couldn't find a clang on macos on godbolt.org.
The failure is due to missing value profiling data.
The `memcpy` calls are not lowered by the FE to the `llvm.memcpy` intrinsic. They are macro expanded to `memcpy_chk` which is not recognized by the value profiling instrumentation.
So memory intrinsics (at least `memcpy`) value profiling is currently broken on macos.


https://github.com/llvm/llvm-project/pull/131177