[Mesa-dev] V4 Loop unrolling in NIR

[Timothy Arceri]

Sorry for the noise. Connor pointed out that some of my assumptions
for not enabling this on all gens were wrong this lead to finding
a subtle bug where loop analysis was being run when is shouldn't
due to an error with the loop analysis flag (0x10 vs 0x16).

This version enabled unrolling for all gens. As well as the bug fix
and dropping the restrictions Patch 1 is also new.

Note: I ran this in Jenkin and it seems ok but I was getting a lot
of noise from failing GLES 3.1 tests on HSW it seems like 3.1 was
enabled on master but not my branch for some reason.