Fix OpenACC 'async'/'wait' issues in 'libgomp.oacc-c-c++-common/lib-{94,95}.c', ...

Fix OpenACC 'async'/'wait' issues in 'libgomp.oacc-c-c++-common/lib-{94,95}.c', 'libgomp.oacc-fortran/lib-16{,-2}.f90'

Fix-up for r265842 (commit 58168bbf6f8fb456280cca13343a498ad94878c7)
"[OpenACC 2.5, libgomp] Add *_async versions of runtime library API functions".

	libgomp/
	* testsuite/libgomp.oacc-c-c++-common/lib-94.c: Fix OpenACC
	'async'/'wait' issue.
	* testsuite/libgomp.oacc-c-c++-common/lib-95.c: Likewise.
	* testsuite/libgomp.oacc-fortran/lib-16-2.f90: Likewise.
	* testsuite/libgomp.oacc-fortran/lib-16.f90: Likewise.

Co-Authored-By: Julian Brown <julian@codesourcery.com>