Fix switch conversion in offloading functions

Fix switch conversion in offloading functions

2018-03-26  Tom de Vries  <tom@codesourcery.com>

	PR tree-optimization/85063
	* omp-general.c (offloading_function_p): New function.  Factor out
	of ...
	* omp-offload.c (pass_omp_target_link::gate): ... here.
	* omp-general.h (offloading_function_p): Declare.
	* tree-switch-conversion.c (build_one_array): Mark CSWTCH.x variable
	with attribute omp declare target for offloading functions.

	* testsuite/libgomp.c/switch-conversion-2.c: New test.
	* testsuite/libgomp.c/switch-conversion.c: New test.
	* testsuite/libgomp.oacc-c-c++-common/switch-conversion-2.c: New test.
	* testsuite/libgomp.oacc-c-c++-common/switch-conversion.c: New test.

From-SVN: r258852