implement codegen of __imag of a scalar.  Our impl doesn't suffer from 
GCC bug PR33192.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@41427 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/CodeGen/CGExprScalar.cpp b/CodeGen/CGExprScalar.cpp
index 91e76aa..9bd5b3f 100644
--- a/CodeGen/CGExprScalar.cpp
+++ b/CodeGen/CGExprScalar.cpp
@@ -393,9 +393,11 @@
   Expr *Op = E->getSubExpr();
   if (Op->getType()->isComplexType())
     return CGF.EmitComplexExpr(Op).second;
-
-  // FIXME: does this evaluate the subexpr??
-  return 0;  // FIXME:  Return zero of the right int/fp type.
+  
+  // __imag on a scalar returns zero.  Emit it the subexpr to ensure side
+  // effects are evaluated.
+  CGF.EmitScalarExpr(Op);
+  return llvm::Constant::getNullValue(ConvertType(E->getType()));
 }