[clang] Fix memcpy-operator= generation with restrict parameters. (PR #194906)

[Aaron Ballman via cfe-commits]

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@@ -15181,7 +15181,7 @@ buildSingleCopyAssign(Sema &S, SourceLocation Loc, QualType T,
                       bool CopyingBaseSubobject, bool Copying) {
   // Maybe we should use a memcpy?
   if (T->isArrayType() && !T.isConstQualified() && !T.isVolatileQualified() &&
-      T.isTriviallyCopyableType(S.Context))
+      !T.isRestrictQualified() && T.isTriviallyCopyableType(S.Context))
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AaronBallman wrote:

The changes here are correct as far as they go, but I actually wonder if we want this predicate to be even more conservative: if there are any qualifiers of any kind or it's an attributed type, just use the for loop version and let CodeGen figure out if that's acceptable to turn back into a memcpy. But I don't insist on a PR for that,

https://github.com/llvm/llvm-project/pull/194906