[clang] [TySan][Clang] Add clang flag to use tysan outlined instrumentation a… (PR #166170)

[Matthew Nagy via cfe-commits]

gbMattN wrote:

I'm not aware of any cases where the outlined instrumentation gives you worse diagnostics than the inlined one, but I think before being comfortable changing the default I will want to do a little more testing. What I've done is a little more "ad-hoc" than exhaustive

https://github.com/llvm/llvm-project/pull/166170