When converting a block pointer to an Objective-C pointer type, extend
the lifetime of the block by copying it to the heap, or else we'll get
a dangling reference because the code working with the non-block-typed
object will not know it needs to copy.

There is some danger here, e.g. with assigning a block literal to an
unsafe variable, but, well, it's an unsafe variable.

llvm-svn: 139451
diff --git a/clang/lib/CodeGen/CGExprComplex.cpp b/clang/lib/CodeGen/CGExprComplex.cpp
index 90e288a4..326fcfa 100644
--- a/clang/lib/CodeGen/CGExprComplex.cpp
+++ b/clang/lib/CodeGen/CGExprComplex.cpp
@@ -414,6 +414,7 @@
   case CK_ObjCProduceObject:
   case CK_ObjCConsumeObject:
   case CK_ObjCReclaimReturnedObject:
+  case CK_ObjCExtendBlockObject:
     llvm_unreachable("invalid cast kind for complex value");
 
   case CK_FloatingRealToComplex: