Fix PR44281, bad RA with global regs.

Fix PR44281, bad RA with global regs.

	PR rtl-optimization/44281
	* hard-reg-set.h (struct target_hard_regs): New field
	x_fixed_nonglobal_reg_set.
	(fixed_nonglobal_reg_set): New macro.
	* reginfo.c (init_reg_sets_1): Initialize it.
	* ira.c (setup_alloc_regs): Use fixed_nonglobal_reg_set instead
	of fixed_reg_set.
	* df-scan.c (df_insn_refs_collect): Asms may reference global regs.

testsuite/
	PR rtl-optimization/44281
	* gcc.target/i386/pr44281.c: New test.

From-SVN: r235809