Add very basic support for vpiModule. Basically it allows to traverse
the module tree to find a variable etc. It does not support more than
vpi_iterate and vpi_scan for vpiModule along basic operations like
vpi_get_str on vpiModule.
The support is added non-intrusively to non-VPI verilator runs. It
essentially:
- Tracks the creation of cell instances and keeps them alive until
the emit phase. They are there converted to scopes if modules.
- Emits empty (don't add anything during construction)
VerilatedScopes for all inlined modules, only for those inlined
modules that are on the hierarchical path to public variables.
- Adds VerilatedHierarchy as abstraction to structure of the
scopes. It is only created for VPI designs. It allows to traverse
the hierarchy from the top (NULL).
Signed-off-by: Stefan Wallentowitz <stefan@wallentowitz.de>
Signed-off-by: Wilson Snyder <wsnyder@wsnyder.org>
