add a bunch of missing prototypes to tests


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@93072 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Sema/implicit-builtin-decl.c b/test/Sema/implicit-builtin-decl.c
index 09ecd23..3d92038 100644
--- a/test/Sema/implicit-builtin-decl.c
+++ b/test/Sema/implicit-builtin-decl.c
@@ -22,7 +22,8 @@
 }
 
 void f2() {
-  fprintf(0, "foo"); // expected-error{{implicit declaration of 'fprintf' requires inclusion of the header <stdio.h>}}
+  fprintf(0, "foo"); // expected-error{{implicit declaration of 'fprintf' requires inclusion of the header <stdio.h>}} \
+   expected-warning {{implicit declaration of function 'fprintf' is invalid in C99}}
 }
 
 // PR2892