re PR tree-optimization/71437 (Performance regression after r235817)

re PR tree-optimization/71437 (Performance regression after r235817)

	PR tree-optimization/71437
	* tree-ssa-dom.c (pfn_simplify): Add basic_block argument.  All
	callers changed.
	(simplify_stmt_for_jump_threading): Add basic_block argument.  All
	callers changed.
	(lhs_of_dominating_assert): Moved from here into tree-vrp.c.
	(dom_opt_dom_walker::thread_across_edge): Remove
	handle_dominating_asserts argument.  All callers changed.
	(record_temporary_equivalences_from_stmts_at_dest): Corresponding
	changes.  Remove calls to lhs_of_dominating_assert.  Other
	uses of handle_dominating_asserts turn into unconditional code
	(simplify_control_stmt_condition_1): Likewise.
	(simplify_control_stmt_condition): Likewise.
	(thread_through_normal_block, thread_across_edge): Likewise.
	* tree-ssa-threadedge.h (thread_across_edge): Corresponding changes.
	* tree-vrp.c (lhs_of_dominating_assert): Move here.  Return original
	object if it is not an SSA_NAME.
	(simplify_stmt_for_jump_threading): Call lhs_of_dominating_assert
	before calling into the VRP specific simplifiers.
	(identify_jump_threads): Remove handle_dominating_asserts
	argument.

From-SVN: r246207