re PR tree-optimization/84841 (ICE: tree check: expected ssa_name, have real_cst in rewrite_expr_tree_parallel, at tree-ssa-reassoc.c:4624)

	PR tree-optimization/84841
	* tree-ssa-reassoc.c (INTEGER_CONST_TYPE): Change to 1 << 4 from
	1 << 3.
	(FLOAT_ONE_CONST_TYPE): Define.
	(constant_type): Return FLOAT_ONE_CONST_TYPE for -1.0 and 1.0.
	(sort_by_operand_rank): Put entries with higher constant_type last
	rather than first to match comments.

	* gcc.dg/pr84841.c: New test.

From-SVN: r258586