* Introduce FunctionReferenceRegistrar
- Track function references created by functors
- Remove ValueStack-held attributes for functors
- Add Function References section to escript program
- Use Function References section in ins_functor
- Update escript version
* Update listfile snapshots
- Remove ValueStack-held attributes created by functors
* Add function reference tracking to function references
- `emit.function_reference` uses funcref registrar + emits that index
- `ins_funcref` uses parameter count + is variadic from prog funcref table
- update listfile snapshots
* Add core-changes
Also: OG compiler debug info for foreach iterator changed to match actual variable name
Adds:
- ast/DebugStatementMarker: for "intrusive debug" (ecompile -i) instructions
- codegen/DebugBlockGuard: pushes and pops debug block #
- format/DebugStoreSerializer: writes .dbg and .dbg.txt files
- representation/DebugBlock: holds parent block # and local variable names for each block
- representation/DebugStore: holds all debug information
