[compiler-rt] [compiler-rt][rtsan] page regions api interception update. (PR #123601)

[Ben Langmuir via llvm-commits]

benlangmuir wrote:

One of the new tests is failing at least on Darwin: https://green.lab.llvm.org/job/llvm.org/job/clang-stage1-cmake-RA-expensive/3192/testReport/

Looks like `memadvise` vs. `posix_madvise` string match is the issue?

```
Death test: RealtimeInvoke(std::forward<Function>(Func))
    Result: died but not with expected error.
  Expected: contains regular expression ".*==ERROR: RealtimeSanitizer: unsafe-library-call.*Intercepted call to real-time unsafe function `madvise` in real-time context!"
Actual msg:
[  DEATH   ] ==73227==ERROR: RealtimeSanitizer: unsafe-library-call
[  DEATH   ] Intercepted call to real-time unsafe function `posix_madvise` in real-time context!
```

https://github.com/llvm/llvm-project/pull/123601