re PR middle-end/71249 (-Wswitch-unreachable false positive for a compound statement containing a used label)

	PR c/71249
	* gimplify.c (gimplify_switch_expr): Look into the innermost lexical
	scope.

	* c-c++-common/Wswitch-unreachable-2.c: New test.

From-SVN: r236649