The proposed VM Spec version 1.3 states that if a local variable has
a generic type, then the Local Variable Table entry for that variable
will contain the generic signature and not the JNI signature.

In order to support existing debuggers, we need to have the
JNI signature available in addition to the generic signature.
This should be done in such away that the existing LVT format
is retained and the new generic signature
info is added in a backward compatible fashion.