re PR tree-optimization/64494 (ICE at -Os and above on x86_64-linux-gnu in duplicate_ssa_name_range_info, at tree-ssanames.c:499)

	PR tree-optimization/64494
	* tree-ssa-loop-im.c (move_computations_dom_walker::before_dom): Also
	clear SSA_NAME_ANTI_RANGE_P flag.

	* gcc.c-torture/compile/pr64494.c: New test.

From-SVN: r219194