backport: re PR target/81766 (ICE in maybe_add_or_update_dep_1, at sched-deps.c:924...

backport: re PR target/81766 (ICE in maybe_add_or_update_dep_1, at sched-deps.c:924 caused by r250815)

	Backported from mainline
	2017-08-08  Richard Biener  <rguenther@suse.de>

	PR middle-end/81766
	* function.c (thread_prologue_and_epilogue_insns): Restore
	behavior of always calling find_many_sub_basic_blocks on
	the inserted prologue.

	* gcc.target/i386/pr81766.c: New testcase.

	2017-08-02  Jakub Jelinek  <jakub@redhat.com>

	PR middle-end/79499
	* function.c (thread_prologue_and_epilogue_insns): Determine blocks
	for find_many_sub_basic_blocks bitmap by looking up BLOCK_FOR_INSN
	of first NONDEBUG_INSN_P in each of the split_prologue_seq and
	prologue_seq sequences - if any.

	* gcc.dg/pr79499.c: New test.

From-SVN: r252854