* all except pol
* pol and includes under defines
* something weird has happened
* remove own folder from include searchpath
* fixed remaining, adapted include style for external headers
* missing include
* initial poc of function expressions
- update grammar
- mock AST builder to return BBoolean(true) for a func expr
- update prettifier for skeleton implementation
* more skeleton work
create AST class FunctionExpression mimicking boolean value
* create ast UserFunction, add to workspace from functexpr
* can generate instructions
* reorg tests; add test for instructions
* can track FunctionDepth in Variable
* can get captures for funcexprs inside funcs.. tbd if this way of nesting works
* Implement create-functor instruction
- Move function depth from Variable to Variables
- Introduce stacking of `Variables` for function expresions via `FunctionVariableScope`
- Add `TOK_FUNCTOR` instruction for 'create-functor'
- Handle emitting a `FunctionExpression` AST node
- Update `emit.declare_variable` and `emit.access_variable` to account for function captures
- Remove `in_function` from instruction generator, as it is tracked via `UserFunction` stack
- Update tests
* Address Discord comments
- Swap pop param order
* Bubble up captured variables through nested functions
* Improve testing infrastructure; add some test cases
* Fix compilation error
* prepend captures to function parameters in funcref mth_call
* update tests
* move from function{} to @{}
* implementation fix
* some more tests
* update docs
* Some cleanup
* fix CI annotation warning
- 'argument': conversion from 'size_t' to 'VariableIndex', possible loss of data
* Address review comments
- Add `passert_always`
- Use better example in docs
* Some cleanup
- Remove unused functions
