[clang][test] Add a RUN line for the bytecode interpreter (llvm#155363)

This test works with the bytecode interpreter, so add some additional
testing.

Author: tbaederr

clang/test/CodeGen/builtins.c

@@ -1,6 +1,7 @@
 // RUN: %clang_cc1 -emit-llvm -o %t %s
 // RUN: not grep __builtin %t
 // RUN: %clang_cc1 -emit-llvm -triple x86_64-darwin-apple -o - %s | FileCheck %s
+// RUN: %clang_cc1 -emit-llvm -triple x86_64-darwin-apple -o - %s -fexperimental-new-constant-interpreter | FileCheck %s
 
 int printf(const char *, ...);