- general refactoring in decl parsing
- restrict charge strength to trireg
- require const vars to be initialized
- forbid const net declarations
- disallow run-on declarations in packages and classes

In places where an optional space was previously allowed, allow any
number of arbitrary whitespace characters, in line with the spec and
other tools.

- remove outdated flexible partial type eq and show instances
- properly disallow incomplete declarations
- disallow var after net type
- remove unused edge case in InterfaceT representation

- support for additional assignment statements in loop initializations
- greatly improved error messaging in these contexts
- decl parser takes in the ending token; significant related refactoring
- pass through elaboration system tasks
- removed non-blocking assignment operator precedence hack
- preliminary nosim test suite for features unsupported by iverilog

- all decl tokens are given an accurate starting position
- key grammar productions return token positions to facilitate the above
- helpers for standardized parse error generation
- replaced annoying pattern-matching type argument restrictions
- moving away from dumping raw decl tokens in error messages

- 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

- automatic pass-through test suite coverage
- fix codegen for interface based typedefs
- allow declaration of generic interface ports in module body
- fix codegen for comments within for loop initialization
- fix codegen of class param decls

- pattern keys now represented as TypeOrExpr
- support for simple integer struct pattern keys

- previously the overrides for parameterized data types could only
  reference data declarations at the module scope
- their use within procedures is still allowed, but cannot currently
  refer to localparams declared within procedures
- add procedure scope location accessors to allow scoped traversals to
  mark where injected items will end up in advance

- disallow using end label alone on blocks
- improved parse error for mismatches
- add label checking for non-block constructs
- allow generate block to have label before begin

- general refactoring throughout
- improved metrics for dropping unneeded modules
- fix re-visiting a converted instance in the same pass

- fix type/expr ambiguity for interface and class parameters
- check for parameter kind mismatch up front
- centralize key logic in ResolveBindings

- variable-size string parameter conversion restricted to modules which
  depend on the size of the string parameter
- string localparams are typed as appropriately sized vectors
- remove ordered parameter binding logic from string param conversion