[clang-tools-extra] [clang-tidy] Fix false positive for generic lambda parameters in readability-non-const-parameter (PR #179051)

[Aditya Singh via cfe-commits]

Aditya26189 wrote:

Thanks for the review! Before I revise, I want to make sure I understand the expected behavior.

Looking at the test expectations for `gh176623()`:
- **V1** with `A<tc>(p)`: Template-dependent constructor → no warning expected ✓
- **V2** with `B(p)`: Non-template-dependent constructor → warning expected ✓

However, I'm observing that generic lambda bodies (even with non-template-dependent code) may not be fully traversed by the AST matchers until instantiation. This would prevent analysis of V2's body entirely.

**Question**: Should V2 produce a warning? 

- **If yes**: I need to investigate why the lambda body isn't being visited by the matchers. Could you confirm that the checker should analyze non-template-dependent expressions within generic lambdas?

- **If no**: Should I update the test expectations so both V1 and V2 have no warnings (consistent treatment of all generic lambda parameters)?

I want to ensure my fix aligns with the intended behavior before proceeding. Thanks!


https://github.com/llvm/llvm-project/pull/179051