revert patch in r139020


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@139029 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprComplex.cpp b/lib/CodeGen/CGExprComplex.cpp
index 24d0115..1a27d13 100644
--- a/lib/CodeGen/CGExprComplex.cpp
+++ b/lib/CodeGen/CGExprComplex.cpp
@@ -311,7 +311,11 @@
 //===----------------------------------------------------------------------===//
 
 ComplexPairTy ComplexExprEmitter::VisitExpr(Expr *E) {
-  return EmitLoadOfLValue(E);
+  CGF.ErrorUnsupported(E, "complex expression");
+  llvm::Type *EltTy =
+  CGF.ConvertType(E->getType()->getAs<ComplexType>()->getElementType());
+  llvm::Value *U = llvm::UndefValue::get(EltTy);
+  return ComplexPairTy(U, U);
 }
 
 ComplexPairTy ComplexExprEmitter::