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

[Marco Elver via cfe-commits]

melver wrote:

@aaronpuchert - RFC regarding basic capability alias analysis.

For the bare minimum this would work, and likely covers 90% of the cases I worry about. I believe later enhancements could be built on top.

There might be something I'm missing though. Kindly take a look.
Many thanks!

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