[clang] Thread Safety Analysis: Basic capability alias-analysis (PR #142955)

[Marco Elver via cfe-commits]

melver wrote:

Squashed the loop-invariant alias fix, so this should address most comments - initially thought I'd preserve the history of how we got here, but this seems cleaner. Also moved the isStaticLocal() fix to the base commit, and the 2nd commit is now only about translateCXXNewExpr().

PTAL.

https://github.com/llvm/llvm-project/pull/142955