CHECK-LABEL-ify some code gen tests to improve diagnostic experience when tests fail.

llvm-svn: 188447
diff --git a/clang/test/CodeGenCXX/constructor-attr.cpp b/clang/test/CodeGenCXX/constructor-attr.cpp
index 691795f..4f6d635 100644
--- a/clang/test/CodeGenCXX/constructor-attr.cpp
+++ b/clang/test/CodeGenCXX/constructor-attr.cpp
@@ -5,7 +5,7 @@
 // PR6521
 void bar();
 struct Foo {
-  // CHECK: define linkonce_odr void @_ZN3Foo3fooEv
+  // CHECK-LABEL: define linkonce_odr void @_ZN3Foo3fooEv
   static void foo() __attribute__((constructor)) {
     bar();
   }