find_first_parameter_load params and return type

find_first_parameter_load params and return type

gcc/
2014-08-28  David Malcolm  <dmalcolm@redhat.com>

	* rtl.h (find_first_parameter_load): Strengthen return type and
	both params from rtx to rtx_insn *.
	* rtlanal.c (find_first_parameter_load): Strengthen return type,
	both params and locals "before", "first_set" from rtx to
	rtx_insn *.  Remove now-redundant cast.
	* except.c (sjlj_mark_call_sites): Use NULL rather than NULL_RTX.

From-SVN: r214695