[clang] Fix cycle in importing template specialization on auto type with typename (PR #162514)

[Oliver Hunt via cfe-commits]

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@@ -4058,7 +4059,13 @@ ExpectedDecl ASTNodeImporter::VisitFunctionDecl(FunctionDecl *D) {
   }
 
   Error Err = Error::success();
+  if (!UsedDifferentProtoType) {
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ojhunt wrote:

silly nit: single statement conditionals shouldn't have braces.

https://github.com/llvm/llvm-project/pull/162514