- dimensions flattening conversion only flattens packed dimensions
- conversion for packing arrays when necessary (preserves memories)
- added coverage for array with multiple packed dimensions
- test runner no longer forbids multi-dim accesses after conversion
- Decl and subordinate types derive Ord

- NestTF refactored to cover all package items
- fixed issue where type traverse skipped typedefs

This also entailed further fleshing out the expression traversal helper
to cover expressions in generate blocks, which could, of course, use
$bits.

- convert default pattern used to fill a vector
- convert Logic in parameter and localparam types
- interface conversion should happen early for type resolution later on
- interface conversion handles renaming of usages of inlined decls