testcase for previous patch!


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@92317 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/Sema/unused-expr.c b/test/Sema/unused-expr.c
index 30f6aee..f5c64e6 100644
--- a/test/Sema/unused-expr.c
+++ b/test/Sema/unused-expr.c
@@ -91,6 +91,7 @@
   fn1();  // expected-warning {{ignoring return value of function declared with warn_unused_result attribute}}
   fn2(92, 21);  // expected-warning {{ignoring return value of function declared with pure attribute}}
   fn3(42);  // expected-warning {{ignoring return value of function declared with const attribute}}
+  __builtin_fabsf(0); // expected-warning {{ignoring return value of function declared with const attribute}}
   return 0;
 }