re PR target/39431 (ICE in spill_failure, at reload1.c:2093)

	PR target/39431
	* config/i386/predicates.md (cmpxchg8b_pic_memory_operand): New
	predicate.
	* config/i386/sync.md (sync_compare_and_swap<mode>,
	sync_compare_and_swap_cc<mode>): For DImode with -m32 -fpic check
	if operands[1] is cmpxchg8b_pic_memory_operand, if not force address
	into a register.
	(sync_double_compare_and_swapdi_pic,
	sync_double_compare_and_swap_ccdi_pic): Require operand 1 to be
	cmpxchg8b_pic_memory_operand instead of just memory_operand.

	* gcc.target/i386/pr39431.c: New test.

From-SVN: r144825