Samplerless read tests don't allow denormal flushing mismatches

The tests do validation per the 1.2 requirement that all samplerless reads behave identically to the equivalent sampler reads. This is relaxed in 2.0 and later but the test kernels still require identical behavior.

Locate the samplerless read validation and its test kernels, then compare how the tests apply the OpenCL 1.2 requirement with the relaxed 2.0-and-later behavior. Done means denormal flushing mismatches remain rejected for 1.2 while being accepted for 2.0 and later.

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