re PR preprocessor/60736 (Crash in preprocessor including stdc-predef.h when it does not exist on glibc-based systems)

	PR preprocessor/60736
	* include/cpplib.h (cpp_errno_filename): New prototype.
	* errors.c (cpp_errno): Don't handle msgid "" specially, use
	_(msgid) instead of msgid as argument to cpp_error.
	(cpp_errno_filename): New function.
	* files.c (read_file_guts): Use cpp_errno_filename instead of
	cpp_errno.
	(open_file_failed): Likewise.  Use file->name if file->path is NULL
	in diagnostics.

From-SVN: r230591
diff --git a/libcpp/include/cpplib.h b/libcpp/include/cpplib.h
index f5c2a21..3cb8cce 100644
--- a/libcpp/include/cpplib.h
+++ b/libcpp/include/cpplib.h
@@ -986,6 +986,9 @@
 /* Output a diagnostic with "MSGID: " preceding the
    error string of errno.  No location is printed.  */
 extern bool cpp_errno (cpp_reader *, int, const char *msgid);
+/* Similarly, but with "FILENAME: " instead of "MSGID: ", where
+   the filename is not localized.  */
+extern bool cpp_errno_filename (cpp_reader *, int, const char *filename);
 
 /* Same as cpp_error, except additionally specifies a position as a
    (translation unit) physical line and physical column.  If the line is