Even more AMD ray tracing performance improvements heading to Mesa on Linux

Measurements on navi31:

Cyberpunk 2077:
Difference at 95.0% confidence
1.12333 +/- 0.42876
1.88216% +/- 0.718391%
(Student's t, pooled s = 0.189165)

Black Myth Wukong benchmark:
Difference at 95.0% confidence
4 +/- 1.30862
13.9535% +/- 4.56495%
(Student's t, pooled s = 0.57735)

Portal with RTX:
66.2ms->61.5ms (~7.64% improvement)