* Support default args in funcref calls
- Simplify BFunctionRef by using funcref index
- Emit default args when visiting function reference
* Move default args gen to second-pass visit
* Better error message on param count errors
* Check for constructor in MTH_NEW
* Address self-review comments
- Update code comments
* Introduce ResourceManager to pol testsuite
- Create a new class-based resource manager for deleting resources
(item NPCs, multis) after each test.
- Migrate house_set_multiid test to use new ResourceManager.
* Move resource cleanup
Adds:
- ast/Block: a block scope that allows declaring local variables
- ast/IfThenElseStatement: AST node for if..elseif..else..endif statements
- model/FlowControlLabel: provides an anchor for jumps or calls.
- Function calls, break statements, continue statements, and loops will all use these.
