Yesterday I found the problem why we get a VerifyError when running Eclipse with CACAO-OpenJDK, while HotSpot does not. It's again the MagicAccessorImpl class.
Snippet from sun/reflect/MagicAccessorImpl.java (I overlooked that when debugging the access-check bug):
The bug fix for 4486457 also necessitated disabling
verification for this class and all subclasses, as
opposed to just
SerializationConstructorAccessorImpl and subclasses, to
avoid
having to indicate to the VM which of these
dynamically-generated
stub classes were known to be able to pass the verifier.
Finding these magics is really a pain...