switch conversion: make a rapid speed up

switch conversion: make a rapid speed up

gcc/ChangeLog:

	PR tree-optimization/96979
	* tree-switch-conversion.c (jump_table_cluster::can_be_handled):
	Make a fast bail out.
	(bit_test_cluster::can_be_handled): Likewise here.
	* tree-switch-conversion.h (get_range): Use wi::to_wide instead
	of a folding.

gcc/testsuite/ChangeLog:

	PR tree-optimization/96979
	* g++.dg/tree-ssa/pr96979.C: New test.

(cherry picked from commit e46858e4eeee45d35ca4a7df1996186fe884879b)