polar compute shader slower on Intel iGPU

Consider using non-compute version on Intel iGPU. And maybe in general avoid compute shaders on those iGPU if they are slower?

13th gen HD770:

<nevcairiel> 'polar':         528 frames in 7.392925 seconds => 14.001752 ms/frame (71.42 FPS), gpu time: 13.904568 ms
<nevcairiel> 'polar_nocompute':       528 frames in 6.788285 seconds => 12.856600 ms/frame (77.78 FPS), gpu time: 12.698809 ms

9.5th gen HD620 (WHL GT2):

<kasper93> 'polar':	  44 frames in 1.616325 seconds => 36.734669 ms/frame (27.22 FPS), gpu time: 36.696965 ms
<kasper93> 'polar_nocompute':	  59 frames in 1.398729 seconds => 23.707274 ms/frame (42.18 FPS), gpu time: 23.690393 ms

UHD600 (GLK 2):

<kasper93> 'polar':	  80 frames in 13.823495 seconds => 172.793692 ms/frame ( 5.79 FPS), gpu time: 172.746593 ms
<kasper93> 'polar_nocompute':	  96 frames in 6.318808 seconds => 65.820914 ms/frame (15.19 FPS), gpu time: 65.813845 ms