libgomp: Only test with configured (supported) offloading devices.
libgomp/
* testsuite/lib/libgomp.exp: Set offload_targets_s, and
offload_targets_s_openacc.
(check_effective_target_openacc_nvidia_accel_selected): Look for
global offload_target_openacc instead of ACC_DEVICE_TYPE
environment variable.
* testsuite/libgomp.oacc-c++/c++.exp: Loop through
offload_targets_s_openacc.
* testsuite/libgomp.oacc-c/c.exp: Likewise.
* testsuite/libgomp.oacc-fortran/fortran.exp: Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/branches/gomp-4_0-branch@218846 138bc75d-0d04-0410-961f-82ee72b054a4