Added support for cl_ext_float_atomics in CBasicTestFetchMinSpecialFloats with atomic_float

[shajder]

Related to #2142, according to the work plan, extending CBasicTestFetchMinSpecialFloats with support for atomic_float.

[bashbaug]

Adding "focused review" after discussion in the February 10th teleconference.

[bashbaug]

Can you check that this test logic is working the way you expect it to work? These tests seem to run significantly longer than the fp16 add special values tests. I found one logic error, but there might be others...

[shajder]

Can you check that this test logic is working the way you expect it to work? These tests seem to run significantly longer than the fp16 add special values tests. I found one logic error, but there might be others...

hmm, I just tested separate CBasicTestFetchMinSpecialFloats test. On both Intel UHD graphics and nvidia GPU devices it executes in "no time". With Intel CPU implementation I got a total freeze while starting SVM part of the test.

One thing I've noticed is worse performance of FP64 regular CBasicTestFetchMin test but it is pretty obvious due to emulation flag switched on (IGC_EnableDPEmulation)

[bashbaug]

Merging as discussed in the March 10th teleconference.