After reporting ill-formed copy constructor(12.8.p3)
don't recurs and crash.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@78323 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaOverload.cpp b/lib/Sema/SemaOverload.cpp
index c28e052..0fb515e 100644
--- a/lib/Sema/SemaOverload.cpp
+++ b/lib/Sema/SemaOverload.cpp
@@ -1344,7 +1344,8 @@
              = ToRecordDecl->lookup(ConstructorName);
            Con != ConEnd; ++Con) {
         CXXConstructorDecl *Constructor = cast<CXXConstructorDecl>(*Con);
-        if (Constructor->isConvertingConstructor())
+        if (!Constructor->isInvalidDecl() &&
+            Constructor->isConvertingConstructor())
           AddOverloadCandidate(Constructor, &From, 1, CandidateSet,
                                /*SuppressUserConversions=*/true, ForceRValue);
       }