use 'diff' rather than 'cmp -s' in a test

That's what all tests use, no idea where I got the latter from.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@207797 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/test/Frontend/rewrite-includes-messages.c b/test/Frontend/rewrite-includes-messages.c
index 37b970669f16dbde68cae8e5e1f344e1df66e75f..b7170afc0e00f6cb28ea38e8bc99a4d855fef9cc 100644 (file)
--- a/test/Frontend/rewrite-includes-messages.c
+++ b/test/Frontend/rewrite-includes-messages.c
@@ -1,6 +1,6 @@
 // RUN: %clang -E -frewrite-includes %s -I%S/Inputs/ | %clang -Wall -Wunused-macros -x c -c - 2> %t.1
 // RUN: %clang -I%S/Inputs/ -Wall -Wunused-macros -c %s 2> %t.2
-// RUN: cmp -s %t.1 %t.2
+// RUN: diff %t.1 %t.2
 // expected-no-diagnostics
 // REQUIRES: shell