support: Implement support_quote_string

Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>

support/support_quote_string.c

@@ -0,0 +1,26 @@
+/* Quote a string so that it can be used in C literals.
+   Copyright (C) 2018 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 <string.h>
+#include <support/support.h>
+
+char *
+support_quote_string (const char *str)
+{
+  return support_quote_blob (str, strlen (str));
+}