[sanitizer] Don't intercept LFS64 symbols on musl

[sanitizer] Don't intercept LFS64 symbols on musl

LFS64 symbols in musl are for glibc-ABI-compat and not intended for linking
(correct usage will not create LFS64 references). The next release 1.2.4 will
disallow linking against LFS64 symbols[1].

For sanitizers, let's just remove LFS64 interceptors. In case of erroneous LFS64
references, asan/tsan will detect fewer problems and msan may have false
positives.

[1]: https://git.musl-libc.org/cgit/musl/commit/?id=246f1c811448f37a44b41cd8df8d0ef9736d95f4

Reviewed By: thesamesam

Differential Revision: https://reviews.llvm.org/D141186