[IR Framework] CPU preconditions are overriden by regular preconditions

If both CPU feature preconditions and regular preconditions are specified for a test, the CPU feature preconditions are ignored and only the regular preconditions are evaluated. The expected behavior is that both sources of preconditions should be evaluated in a conjunction.

The problem can be reproduced by following these steps:
1. Download and copy the attached reproducer file to test/hotspot/jtreg/compiler/Reproducer.java.
2. Run $ make run-test TEST="compiler/Reproducer.java"

The test "testApplyBoth()" should pass since the conjunction of its preconditions is false, however it fails because only the regular precondition ("applyIf") is evaluated.