Handle queue types and expressions at pform level.
Support declaring queue variables all the way to vvp.

Nothing actually useful happens here, but the declarations
are functional.
vvp code generation for push_back/push_front for queue objects.
Elaborate size method of darray/queue objects.
Implement the size method for queues.

This works by translating it to a $size() system function call.
The $size function is already implemented for dynamic queues and
it is easy enough to expand it for queues.
Non-synthesis version of the devel-stub.sh by default.
Array access to queue variables.
Add support for dynamic array/queue "last" index ($)

Internally, treat the "$" as a special expression type that takes
as an argument the signal that is being indexed. In the vvp target,
use the $last system function to implement this.
Fix mis-spelled vpiStatisARray in sv_vpi_user.h header file
Elaborate pop_back/pop_front methods on dynamic arrays.
Add vvp implementations for pop_back and pop_front methods.
Elaborate foreach loops as synthetic for loops.

Create an implicit scope to hold the index variable, and
generate a for loop to perform the functionality of the
foreach.
Implement $low() for certain types.
Clean up some bugs introduced by recent patches.
Sorry message for multi-dimension foreach loop indices.