Revert "Merge pull request #3342 from alalek:perf_stability_check"

This reverts commit 1fbad26fe3a6a47e4b04d91f0273b60da5866900, reversing
changes made to caba92f2b8d03d777ffe6fce501995ea4490f08c.
Revert "Merge pull request #3284 from vbystricky:oclopt_stereoBM"

This reverts commit caba92f2b8d03d777ffe6fce501995ea4490f08c, reversing
changes made to 63383ef1d8bcd5df7198e753d410b2316ae57d56.
Revert "Merge pull request #3368 from alalek:amd_clfinish"

This reverts commit 63383ef1d8bcd5df7198e753d410b2316ae57d56, reversing
changes made to e40567eaeeac42dd9dfd4791812fa866df84c206.