In the timeframe of JDK 8, we added support in jtreg for running tests with JCov, to get test coverage, including basic coverage of a changes. This support broke with the advent of modularization, and has since been superseded by support for JCov in the JDK build, including changeset coverage.

Given the improved and more flexible support in the JDK build, there is no need to maintain or fix the old code in jtreg, and the support can reasonably be deleted.