support: Add support for delayed test failure reporting

The new functions support_record_failure records a test failure,
but does not terminate the process.  The macros TEST_VERIFY
and TEST_VERIFY_EXIT check that a condition is true.

support/support_test_verify_impl.c

@@ -0,0 +1,33 @@
+/* Implementation of the TEST_VERIFY and TEST_VERIFY_EXIT macros.
+   Copyright (C) 2016 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <support/check.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+
+void
+support_test_verify_impl (int status, const char *file, int line,
+                          const char *expr)
+{
+  support_record_failure ();
+  printf ("FAIL %s:%d: not true: %s\n", file, line, expr);
+  if (status >= 0)
+    exit (status);
+
+}