Alternative to `_change_notify()` to be called from within C++ classes.
Achieves low-level consistency with scripting, where this method is
exposed for updating the editor (inspector) with new values.
- ClassDoc added to GDScript and property reflection data were extracted
from parse tree
- GDScript comments are collected from tokenizer for documentation and
applied to the ClassDoc by the GDScript compiler
- private docs were excluded (name with underscore prefix and doesn't
have any doc comments)
- default values (of non exported vars), arguments are extraced from the
parser
- Integrated with GDScript 2.0 and new enums were added.
- merge conflicts fixed
ptrcall is now also used to optimize calls in GDScript, on top of the existing
use by the GDNative and Mono modules.
It no longer makes sense to make it optional.