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

llvm-svn: 188447
diff --git a/clang/test/CodeGenCXX/alloca-align.cpp b/clang/test/CodeGenCXX/alloca-align.cpp
index 99d6ab5..079b55d 100644
--- a/clang/test/CodeGenCXX/alloca-align.cpp
+++ b/clang/test/CodeGenCXX/alloca-align.cpp
@@ -6,19 +6,19 @@
   int TheStores __attribute__((aligned(16)));
 };
 
-// CHECK: define void @f0
+// CHECK-LABEL: define void @f0
 // CHECK: alloca %struct.s0, align 16
 extern "C" void f0() {
   (void) s0();
 }
 
-// CHECK: define void @f1
+// CHECK-LABEL: define void @f1
 // CHECK: alloca %struct.s0, align 16
 extern "C" void f1() {
   (void) (struct s0) { 0, 0, 0, 0 };
 }
 
-// CHECK: define i32 @f2
+// CHECK-LABEL: define i32 @f2
 // CHECK: alloca %struct.s1, align 2
 struct s1 { short x; short y; };
 extern "C" struct s1 f2(int a, struct s1 *x, struct s1 *y) {