[clang] [llvm] [Sanitizer] Make sanitizer passes idempotent (PR #99439)

[Fangrui Song via llvm-commits]

MaskRay wrote:

> > I remain concerned that newly developed instrumentations may require this special property. Is it useful to restrict this to HIP programs, at least before we gain more experience to comfortably apply this to other configurations?
> > I'm also worried that this change could mask potential pass pipeline issues arising from duplicate instrumentations.
> 
> This is also not HIP specific. Anyway as @vitalybuka noted, the default is to complain.

OK, I see. [Instrumentation.cpp](https://github.com/llvm/llvm-project/pull/99439/files#diff-119f6c3c748edab915c15d7fd22306516ceee28a75ddf8ac52794a8e68ac7722) reports an error by default. This addresses my concern, but now the subject and commit message are incorrect.

https://github.com/llvm/llvm-project/pull/99439