[clang] [clang-tools-extra] [Clang][Sema] Diagnose class member access expressions naming non-existent members of the current instantiation prior to instantiation in the absence of dependent base classes (PR #84050)

[Nikita Popov via cfe-commits]

nikic wrote:

FYI this change has some visible compile-time impact, with some 0.5-1% regressions on various LLVM files (https://llvm-compile-time-tracker.com/compare_clang.php?from=2f2e31c3c980407b2660b4f5d10e7cdb3fa79138&to=a8fd0d029dca7d17eee72d0445223c2fe1ee7758&stat=instructions%3Au&sortBy=interestingness). Nothing terrible (it doesn't seem to be an across-the-board regression), just wanted to let you know in case this is unexpected.

https://github.com/llvm/llvm-project/pull/84050