Few of the tests in langtools regression ws, need an rt.jar to run the tests. Replacing this rt.jar with a new dummy foo.jar does not have the same effect for testing a given test case. So, we need a new dummy rt.jar which can be used for these tests.

One of tests that needs a rt.jar: test/tools/javac/T8009640/CheckRejectProfileBCPOptionsIfUsedTogetherTest.java