tree-switch-conversion.c (struct switch_conv_info): Add range_max, reorganize some fields and update comments.

gcc/
	* tree-switch-conversion.c (struct switch_conv_info): Add range_max,
	reorganize some fields and update comments.  Rename bit_test_uniq
	and bit_test_count to uniq resp. count.  Remove bit_test_bb.
	(collect_switch_conv_info): New function, collects info about a
	GIMPLE_SWITCH into a struct switch_conv_info.
	(check_range): Simplify to use pre-recorded info.  Fix think-o in
	range-branch ratio check.
	(check_process_case): Remove function.
	(check_all_empty_except_final): New function, verifies that all
	non-final basic blocks are empty.
	(process_switch): Simplify to use pre-recorded info.  Call
	collect_switch_conv_info to do that.  Assert that degenerate switch
	statements have been cleaned up.

From-SVN: r186901