[clang] [Clang] Check consteval calls in lambda init-captures (PR #229953)

[via cfe-commits]

beanscrack wrote:

@Fznamznon @zwuis @shafik — follow-ups are in: added the consteval copy-constructor capture test, mixed-capture regression coverage, updated the source-location expectation, and the release note. CI is green. PTAL, thanks!

https://github.com/llvm/llvm-project/pull/229953