Adding initial commit for measurement performance of runtime overhead

[kamdiedrich]

This is initial commit for measurement performance run-time overhead, in next steps there will be extended testing values (e.g. LWS, events) and test cases

[krrishnarraj]

Sorry for the late response.
What exactly are these tests trying to measure? I did run them, but was not sure what it was displaying

[MichalMrozek]

Those tests measure CPU driver overhead for various API calls.
They show how long it takes to execute given API (i.e. clEnqueueNDRangeKernel) in various conditions ( multiple threads, different parameter sets, etc. )