[clang] [Multilib] Expose sanitizer flags as multilib flags (PR #182350)

[Victor Campos via cfe-commits]

https://github.com/vhscampos commented:

I suggest you move the exposition of sanitizer flags into the target-specific filtering for the target you are doing the work for, rather than exposing them for all targets.

In the future if we know that more than one target needs them, we could consider moving it back to the generic filtering

https://github.com/llvm/llvm-project/pull/182350