* Merge 'decorators' into 'modifiers' on various Nodes
* Drop RESERVED argument in favor of removing parameter
* Ignore grammar error nodes when asserting invariants
* Revert 'illegalX' property renames
* PR Feedback
* Refactor node factory API, use node factory in parser
* Move UnparsedSource nodes to factory
* Make most Node properties read-only
* Make pos/end/parent and JSDoc 'comment' read-only
* Update function/constructor-type factories
* Remove treeStateObserver
* Simplify Debug.deprecate
* Remove unused factory methods, simplify lazy factory methods
* Fix base factory used for source file updates
* Update test baseline due to merge from master
* Rename factory methods to be more consistent (#39058)