Add local tag support. Don't flush instructions for .xdata directives.

Add local tag support.  Don't flush instructions for .xdata directives.
	* config/tc-ia64.c (md): New member keep_pending_output.
	(ia64_flush_pending_output): Flush only if md.keep_pending_output
	is not set.
	(dot_xdata): Turn on md.keep_pending_output for the duration of
	this function.
	(dot_xfloat_cons): Ditto.
	(dot_xstringer): Ditto.
	(dot_xdata_ua): Ditto.
	(dot_xfloat_cons_ua): Ditto.
	* config/tc-ia64.c (ia64_unrecognized_line, case '['): Add local
	label support.