Fix liveness analysis in lra for spilled-into hard regs

Fix liveness analysis in lra for spilled-into hard regs

2018-03-01  Tom de Vries  <tom@codesourcery.com>

	PR rtl-optimization/83327
	* lra-int.h (hard_regs_spilled_into): Declare.
	* lra.c (hard_regs_spilled_into): Define.
	(init_reg_info): Init hard_regs_spilled_into.
	* lra-spills.c (assign_spill_hard_regs): Update hard_regs_spilled_into.
	* lra-lives.c (make_hard_regno_born, make_hard_regno_dead)
	(process_bb_lives): Handle hard_regs_spilled_into.
	(lra_create_live_ranges_1): Before doing liveness propagation, clear
	regs in all_hard_regs_bitmap if set in hard_regs_spilled_into.

From-SVN: r258093