[clang] [clang] Improve checking of operator functions (PR #131777)

[via cfe-commits]

================
@@ -330,6 +331,13 @@ Bug Fixes to C++ Support
 - Fixed an assertion failure affecting code that uses C++23 "deducing this". (#GH130272)
 - Clang now properly instantiates destructors for initialized members within non-delegating constructors. (#GH93251)
 - Correctly diagnoses if unresolved using declarations shadows template paramters (#GH129411)
+- Invalid operator function signatures generated from templates during
+  overload resolution are now eliminated from the candidate set without making
+  the program ill-formed. (#GH49197)
+- Binary operator function templates with a single parameter are no longer
+  rejected when that parameter is a pack.
+- Fixed operator functions without a class or enumeration parameter not being
+  rejected when an explicit object parameter is present.
----------------
Sirraide wrote:

Hmm, we usually only have one release note per pr. Also, the other issues that this fixes should be listed here as well.

https://github.com/llvm/llvm-project/pull/131777