Revert "[sanitizer] Define SANITIZER_GLIBC to refine SANITIZER_LINUX feature...

Revert "[sanitizer] Define SANITIZER_GLIBC to refine SANITIZER_LINUX feature detection and support musl"

...and follow-ups. It still doesn't build on Android, see https://reviews.llvm.org/D93848#2476310

This reverts commit a92d0153.
This reverts commit 52d7e183.
This reverts commit 34489da8.