Radically simplify emission of balanced tree for switch statements.

Radically simplify emission of balanced tree for switch statements.

2018-05-18  Martin Liska  <mliska@suse.cz>

	* passes.def: Add pass_lower_switch and pass_lower_switch_O0.
	* tree-pass.h (make_pass_lower_switch_O0): New function.
	* tree-switch-conversion.c (node_has_low_bound): Remove.
	(node_has_high_bound): Likewise.
	(node_is_bounded): Likewise.
	(class pass_lower_switch): Make it a template type and create
	two instances.
	(pass_lower_switch::execute): Add template argument.
	(make_pass_lower_switch): New function.
	(make_pass_lower_switch_O0): New function.
	(do_jump_if_equal): Remove.
	(emit_case_nodes): Simplify to just handle all 3 cases and leave
	all the hard work to tree optimization passes.
2018-05-18  Martin Liska  <mliska@suse.cz>

	* gcc.dg/tree-ssa/vrp104.c: Adjust dump file that is scanned.
	* gcc.dg/tree-prof/update-loopch.c: Likewise.

From-SVN: r260350