[clang-tools-extra] [clang-tidy] Add recursion protection in ExceptionSpecAnalyzer (PR #66810)

[Piotr Zegar via cfe-commits]

PiotrZSL wrote:

> This class could maintain a stack-like `SmallVector` to check for an infinite recursion., so instead of checking the function cache (which might be large), only a few functions have to be compared this way.

Actually this change does not impact performance. Before we had 2 lookups, and now we still got 2 lookups.

https://github.com/llvm/llvm-project/pull/66810