backport: re PR target/51784 (PIC register not correctly preserved in nested funcs...

backport: re PR target/51784 (PIC register not correctly preserved in nested funcs / with non-local goto)

gcc:
	Backport from mainline:
	2013-07-22  Uros Bizjak  <ubizjak@gmail.com>

	* config/i386/i386.md (nonlocal_goto_receiver): Delete insn if
	it is not needed after split.

	2013-07-20  Iain Sandoe  <iain@codesourcery.com>

	PR target/51784
	* config/i386/i386.c (output_set_got) [TARGET_MACHO]: Adjust to emit a
	second label for nonlocal goto receivers. Don't output pic base labels
	unless we're producing PIC; mark that action unreachable().
	(ix86_save_reg): If the function contains a nonlocal label, save the
	PIC base reg.
	* config/darwin-protos.h (machopic_should_output_picbase_label): New.
	* gcc/config/darwin.c (emitted_pic_label_num): New GTY.
	(update_pic_label_number_if_needed): New.
	(machopic_output_function_base_name): Adjust for nonlocal receiver
	case.
	(machopic_should_output_picbase_label): New.
	* config/i386/i386.md (enum unspecv): UNSPECV_NLGR: New.
	(nonlocal_goto_receiver): New insn and split.

From-SVN: r202147