Summary: Catch missing-because-illegal case for itable entries and use an exception-throwing method instead of null.
Reviewed-by: acorn, jrose, coleenp

8025260: Methodhandles/JSR292: NullPointerException (NPE) thrown instead of AbstractMethodError (AME)
Summary: Copied null-checks from templateInterpreter_CPU into methodHandles_CPU
Reviewed-by: jrose, twisti