MC: remove unnecessary restriction on tests

Rafael correctly pointed out that the restriction is unnecessary.  Although the
tests are intended to ensure that we dont abort due to an assertion, running the
tests in all modes is better since it also ensures that we dont crash without
assertions.  Always run these tests to ensure that we can handle invalid input
correctly.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@209496 91177308-0d34-0410-b5e6-96231b3b80d8