- references to other instances are no longer flagged
- special handling for genvars to avoid flagging and modport scoping
- interface inlining visits expressions in declarations
- Scoper has interface for removing entries

The interface conversion no longer substitutes parameters immediately,
instead fully scoping modports and allowing hierarchical constants to be
resolved separately. This fixes an issue where struct parameters could
lose their type information during substitution. The conversion also now
handles renaming references to the module or interface top-level scope.

- remove needless comments generated during interface conversion
- filter null statements even in verbose mode
- hoist trace comment statements if doing so would prevent the need to
  wrap a task or function body in a block
- add traces for global declarations
- add traces for parameter declaration lists
- add traces for module items within generate blocks
- avoid generating duplicate traces before declarations

- new net decl to replace net pseudo-type
- support nets with complex base types, including typenames
- support var declaration type prefix for all data types
- support var as lone type shorthand
- refactor AST representation of strengths
- traversal helpers for treating nets as variables
- use decl traversals where appropriate

- error for unbound module instance interface ports
- warning for converting an interface alone
- warning for converting a package alone
- update terminology for modules removed by interface conversion

- support for interface instance arrays
- support for interface-using module instance arrays
- support for modport array bindings
- fix modport bindings shadowed in nested instances

- module instances with modport bindings are now inlined
- support for modports in generate loops
- support for generic interfaces
- implied modport instance propagation
- add error message for interface instances missing port list

- interface conversion only waits for type resolution of modports
- typeof conversion resolves struct field accesses
- logic conversion only converts logic data declarations
- struct conversion only converts within modules
- fix nested type traversal order causing premature struct conversion

- modports can use complex expressions
- update interface_infer test for consistency across simulators
- fix interface inlining of implicitly typed data declarations

- fix position modport-to-modport bindings
- inout logics converted to regs become outputs

- also fixes an issue where system tasks were inadvertently prefixed
  during the interface conversion