This adds a conformance test which renders a texture point using a 2x2
texture with a different color for each texel. It then verifies that
each texel is mapped to the correct position on the point. The test is
currently failing.
The test requires the point sprite feature flag so this patch also
adds a TEST_REQUIREMENT_* flag for that.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
