re PR tree-optimization/42963 (Redundant switch labels not cleaned up anymore)
PR tree-optimization/42963
* tree-cfg.c (touched_switch_bbs): New static variable.
(group_case_labels_stmt): New function broken out from ...
(group_case_labels): ... here, use the above.
(start_recording_case_labels): Allocate touched_switch_bbs.
(end_recording_case_labels): Deallocate it, call
group_case_labels_stmt.
(gimple_redirect_edge_and_branch): Remember index of affected BB.
testsuite/
* testsuite/gcc.dg/pr42963.c: New testcase.