[sv-ac] 1549 new types uploaded

I have uploaded round #2 of the new types proposal.  Changes from the
first include:

 

a) change "anytype" to "implicit"  as suggested by Bassom

b) define event as any event_expression and remove references to
event_controls (hierarchical_event_identifier, *, and (*)) I now agree
with Bassom that these event_controls cannot be passed as actuals and
should not be supported.

 

Lisa