Make this test portable to ABIs that use sret.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@97035 91177308-0d34-0410-b5e6-96231b3b80d8

test/CodeGen/functions.c

@@ -30,7 +30,7 @@ void f2(void) {
 // CHECK: define void @f1()
 void f1() {}
 
-// CHECK: define {{.*}} @f3()
+// CHECK: define {{.*}} @f3{{\(\)|\(.*sret.*\)}}
 struct foo { int X, Y, Z; } f3() {
   while (1) {}
 }