JAV2I12 — mapping of java.lang.Exception

Summary: I took another look at 28.3.7.1, and I think that the current
special-case mapping of java.lang.Exception is odd and unnecessary.
It seems to me that the right thing to do is to simply remove this
special case, and map it the same as any other exception. So,
java.lang.Exception should map to a valuetype that has
::java::lang::Throwable as a superclass and no data fields, and to an
IDL exception of ::java::lang::Ex (note that this exception is used in
an example in 28.3.4.6). java.lang.Throwable should map to a valuetype
that has no superclass and a private data field named detailMessage, and
to an IDL exception of ::java::lang::ThrowableEx.

Closed, accepted