AArch64: Fix silly think-o in tests.

rdar://9283021

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@211064 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/builtins-arm64.c

@@ -6,11 +6,11 @@ void f0(void *a, void *b) {
 }
 
 // CHECK: call {{.*}} @llvm.aarch64.rbit.i32(i32 %a)
-void rbit(unsigned a) {
-  __builtin_arm_rbit(a);
+unsigned rbit(unsigned a) {
+  return __builtin_arm_rbit(a);
 }
 
 // CHECK: call {{.*}} @llvm.aarch64.rbit.i64(i64 %a)
-void rbit64(unsigned long long a) {
-  __builtin_arm_rbit64(a);
+unsigned long long rbit64(unsigned long long a) {
+  return __builtin_arm_rbit64(a);
 }