Avoid crashing when an input file could not be opened

	* input.c (add_file_to_cache_tab): Handle the case where fopen
	returns NULL.

Signed-off-by: Dodji Seketeli <dodji@seketeli.org>

From-SVN: r207046

gcc/ChangeLog

+2014-01-24  Dodji Seketeli  <dodji@redhat.com>
+
+	* input.c (add_file_to_cache_tab): Handle the case where fopen
+	returns NULL.
+
 2014-01-23  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/59929

gcc/input.c

@@ -293,11 +293,8 @@ add_file_to_cache_tab (const char *file_path)
 {
 
   FILE *fp = fopen (file_path, "r");
-  if (ferror (fp))
-    {
-      fclose (fp);
-      return NULL;
-    }
+  if (fp == NULL)
+    return NULL;
 
   unsigned highest_use_count = 0;
   fcache *r = evicted_cache_tab_entry (&highest_use_count);