re PR bootstrap/64676 (SEGV in tree-ssa-structalias.c solve_constraint)

re PR bootstrap/64676 (SEGV in tree-ssa-structalias.c solve_constraint)

gcc/

	PR bootstrap/64676
	Revert:
	2015-01-19  Igor Zamyatin  <igor.zamyatin@intel.com>

	PR rtl-optimization/64081
	* loop-iv.c (def_pred_latch_p): New function.
	(latch_dominating_def): Allow specific cases with non-single
	definitions.
	(iv_get_reaching_def): Likewise.
	(check_complex_exit_p): New function.
	(check_simple_exit): Use check_complex_exit_p to allow certain cases
	with exits not executing on any iteration.

gcc/testsuite/

	PR bootstrap/64676
	Revert:
	2014-01-19  Igor Zamyatin  <igor.zamyatin@intel.com>

	PR rtl-optimization/64081
	* gcc.dg/pr64081.c: New test.

From-SVN: r219880