* Change setup code in `KernelCode()` to use `_explicit` builtin
variants that are common to both OpenCL-2.X and OpenCL-3.0.
* Only test optional supported builtin variants (`_explicit` signature
memory_order/scope) for OpenCL-3.0.
* Disable program scope global variable and generic address space tests
for a OpenCL-3.0 driver which does not optionally support these
features.
* Test minimum memory consistency capabilities for a device reporting >= 3.0.
Skip tests where unsupported memory consistency capabilities are being requested.
* Pass nullptr as program build option.
Allows the CTS framework to select an appropriate CL C version.
* Removed redundant braces.
