[binutils-gdb] GDB: Fix some null pointer dereferences due to disassembler-options patch.

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT f7bb4e3a0d3738e8cce3dcded6ef12c9949cb85f ***

Author: Peter Bergner <bergner@vnet.ibm.com>
Branch: master
Commit: f7bb4e3a0d3738e8cce3dcded6ef12c9949cb85f

GDB: Fix some null pointer dereferences due to disassembler-options patch.

gdb/
	* gdbarch.sh (pstring_ptr): New static function.
	(gdbarch_disassembler_options): Use it.
	(gdbarch_verify_disassembler_options): Print valid_disassembler_options,
	not valid_disassembler_option->name.
	* gdbarch.c: Regenerate.