* except.c (remove_unreachable_regions): New.
(free_eh_status): Clear exception_handler_labels.
(convert_from_eh_region_ranges): Call remove_unreachable_regions.
(find_exception_handler_labels): Don't add the same label more than
once.
(remove_exception_handler_label): Don't die if
find_exception_handler_labels hasn't been called for the current
function yet.
From-SVN: r48845
