tests: add reg-spilling
When Intel hardware spills registers, it makes use of a buffer called scratch space. Mesa calculates its size, but historically it has made mistakes in this size calculation for compute shaders. Let's add a test that fails when the scratch buffers are smaller than they need to be, so we have a better way to detect these issues.
The last instance of this bug was detected as Aztec ruins just not rendering at all. Having a piglit that fails would be a significant improvement.
Signed-off-by: Paulo Zanoni
This is related to mesa!3612