From: Sanimir Agovic <sanimir.agovic@intel.com>

From: Sanimir Agovic <sanimir.agovic@intel.com>

null ptr check to prevent gdbserver from crashing

Evaluating a thread local storage variable in a remote scenario crashes
gdbserver if libthread-db could not be loaded.

2013-02-12  Sanimir Agovic  <sanimir.agovic@intel.com>

gdbserver/
	* thread-db.c (thread_db_get_tls_address):
	NULL pointer check thread_db.

testsuite/
	* gdb.server/no-thread-db.exp: New file.
	* gdb.server/no-thread-db.c: New file.
	* gdb.server/Makefile.in (EXECUTABLES): Add no-thread-db.