Add $_memeq, $_regex, $_streq, $_strlen convenience functions.

* NEWS: Document them.
	* data-directory/Makefile.in (PYTHON_FILES): Add function/__init__.py,
	function/strfns.py.
	* python/py-type.c (typy_array_1): New function.
	(typy_array): Call it.
	(typy_vector): New function.
	(type_object_methods): Add "vector".
	* python/lib/gdb/function/__init__.py: New file.
	* python/lib/gdb/function/strfns.py: New file.

	doc/
	* gdb.texinfo (Convenience Funs): New node.
	(Types In Python): Document Type.vector.

	testsuite/
	* gdb.python/py-strfns.c: New file.
	* gdb.python/py-strfns.exp: New file.
	* gdb.python/py-type.exp (test_fields): Add vector tests.

gdb/testsuite/gdb.python/py-strfns.c

@@ -0,0 +1,50 @@
+/* This testcase is part of GDB, the GNU debugger.
+
+   Copyright 2012 Free Software Foundation, Inc.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program 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 General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+const char str1[] = "Hello.";
+const char str2[] = "Hello.";
+const char str3[] = "Goodbye.";
+
+const char buf1[] = { 0, 1, 2, 3 };
+const char buf2[] = { 0, 1, 2, 3 };
+const char buf3[] = { 0, 1, 2, 4 };
+
+static void
+func (const char *arg)
+{
+  return; /* Break func here.  */
+}
+
+static void
+bfunc (const char *arg)
+{
+  return; /* Break bfunc here.  */
+}
+
+int
+main ()
+{
+  func (str1);
+  func (str2);
+  func (str3);
+
+  bfunc (buf1);
+  bfunc (buf2);
+  bfunc (buf3);
+
+  return 0;
+}