[llvm-branch-commits] [clang] [Clang] Improve type traits recognition in `__has_builtin` (#111516) (PR #111660)

[Aaron Ballman via llvm-branch-commits]

AaronBallman wrote:

> @tru This change breaks use of llvm 19.1.2 and 19.1.3 #113125 Can it be reverted on the release branch?

Oof, that's unfortunate because this is cherry picking a fix where Clang 19 started returning `false` for `__has_builtin(__reference_binds_to_temporary)` when it was previously reporting `true` which is a pretty important bug to fix.

CC @cor3ntin @timsong-cpp

Note, WG21 meetings are happening next week and so folks are currently traveling and may not respond in a timely manner.

https://github.com/llvm/llvm-project/pull/111660