[clang] [Clang] Fix an assertion in the resolution of perfect matches (PR #140073)

[Alexander Kornienko via cfe-commits]

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@@ -430,8 +430,14 @@ class Sema;
       if (!ReferenceBinding) {
 #ifndef NDEBUG
         auto Decay = [&](QualType T) {
-          return (T->isArrayType() || T->isFunctionType()) ? C.getDecayedType(T)
-                                                           : T;
+          T = (T->isArrayType() || T->isFunctionType()) ? C.getDecayedType(T)
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alexfh wrote:

Since it's not a single expression any more, a simple `if` would be a bit nicer here, IMO.

https://github.com/llvm/llvm-project/pull/140073