If there is an error during HiddenClassDefiner class initialization, record the state in a public boolean field. Change UnsafeClassDefiner to check HiddenClassDefiner state and set UNSAFE_DEFINER as null if there's an error. An IllegalStateException is thrown if HiddenClassDefiner.define() is called in that case.

If there is an error during HiddenClassDefiner class initialization, record the state in a public boolean field. Change UnsafeClassDefiner to check HiddenClassDefiner state and set UNSAFE_DEFINER as null if there's an error. An IllegalStateException is thrown if HiddenClassDefiner.define() is called in that case. #684