Don't #include <stdio.h> when tests don't need it, or use clang instead of clang-cc when they do.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@89070 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/CodeGen/builtins.c b/test/CodeGen/builtins.c
index b4db48a..11bcc14 100644
--- a/test/CodeGen/builtins.c
+++ b/test/CodeGen/builtins.c
@@ -1,7 +1,7 @@
 // RUN: clang-cc -emit-llvm -o %t %s
 // RUN: not grep __builtin %t
 
-#include <stdio.h>
+int printf(const char *, ...);
 
 void p(char *str, int x) {
   printf("%s: %d\n", str, x);