[AArch64] Make the test for rsr and rsr64 stricter

[phosek]

Summary

ACLE specifies that return type for rsr and rsr64 is uint32_t and
uint64_t respectively. D56852 change the return type of rsr64 from
unsigned long to unsigned long long which at least on Linux doesn't
match uint64_t, but the test isn't strict enough to detect that
because compiler implicitly converts unsigned long long to uint64_t,
but it breaks other uses such as printf with PRIx64 type specifier.
This change makes the test stricter enforcing that the return type
of rsr and rsr64 builtins is what is actually specified in ACLE.

[efriedma]

LGTM

cfe/trunk/test/CodeGen/builtins-arm64.c

 // RUN: %clang_cc1 -triple arm64-unknown-linux -disable-O0-optnone -emit-llvm -o - %s | opt -S -mem2reg | FileCheck %s
+#include <stdint.h>
 
 void f0(void *a, void *b) {
   __clear_cache(a,b);
 // CHECK: call {{.*}} @__clear_cache
 }
 
 void *tp (void) {
   return __builtin_thread_pointer ();
// CHECK: call {{.*}} @llvm.prefetch(i8* null, i32 0, i32 0, i32 1)
 
   __builtin_arm_prefetch(0, 0, 0, 1, 1); // pldl1strm
 // CHECK: call {{.*}} @llvm.prefetch(i8* null, i32 0, i32 0, i32 1)
 
   __builtin_arm_prefetch(0, 0, 0, 0, 0); // plil1keep
 // CHECK: call {{.*}} @llvm.prefetch(i8* null, i32 0, i32 3, i32 0)
 }
 
-unsigned rsr() {
+__typeof__(__builtin_arm_rsr("1:2:3:4:5")) rsr(void);
+
+uint32_t rsr() {
   // CHECK: [[V0:[%A-Za-z0-9.]+]] = call i64 @llvm.read_register.i64(metadata ![[M0:[0-9]]])
   // CHECK-NEXT: trunc i64 [[V0]] to i32
   return __builtin_arm_rsr("1:2:3:4:5");
 }
 
-unsigned long rsr64() {
+__typeof__(__builtin_arm_rsr64("1:2:3:4:5")) rsr64(void);
+
+uint64_t rsr64() {
   // CHECK: call i64 @llvm.read_register.i64(metadata ![[M0:[0-9]]])
   return __builtin_arm_rsr64("1:2:3:4:5");
 }
 
 void *rsrp() {
   // CHECK: [[V0:[%A-Za-z0-9.]+]] = call i64 @llvm.read_register.i64(metadata ![[M0:[0-9]]])
   // CHECK-NEXT: inttoptr i64 [[V0]] to i8*
   return __builtin_arm_rsrp("1:2:3:4:5");