Add new internal problem for demangler warnings

Add new internal problem for demangler warnings

This commit adds a new category of internal problem for demangler
warnings.  Demangler warnings behave in much the same way as internal
warnings except that they do not create core files and no option to
change this is presented to the user.

gdb/
2014-06-19  Gary Benson  <gbenson@redhat.com>

	* utils.h (demangler_vwarning): New declaration.
	(demangler_warning): Likewise.
	* utils.c (struct internal_problem)
	<user_settable_should_quit>: New field.
	<user_settable_should_dump_core>: Likewise
	(internal_error_problem): Add values for above new fields.
	(internal_warning_problem): Likewise.
	(demangler_warning_problem): New static global.
	(demangler_vwarning): New function.
	(demangler_warning): Likewise.
	(add_internal_problem_command): Selectively add commands.
	(_initialize_utils): New internal problem command.
	* maint.c (maintenance_demangler_warning): New function.
	(_initialize_maint_cmds): New command.

gdb/doc/
2014-06-19  Gary Benson  <gbenson@redhat.com>

	* gdb.texinfo (Maintenance Commands): Document new
	"maint demangler-warning" command and new
	"maint set/show demangler-warning" option.