Single underscore node name is ignored when using the $ get_node() shorthand

[zhyrin0]

Tested versions

4.3.beta1, 4.3.beta3

System information

Linux Mint 21.3 (Virginia)

Issue description

When working with $ shorthand node paths in gdscript, a single underscore node name gets ignored.
Example:

SceneRoot
\- _
   \- Node
\- Sibling
   \- _
      \- Node

Here, $_/Node gets recognised as /Node, $Sibling/_/Node gets recognised as Sibling/Node.

Steps to reproduce

• Create a scene
• Add a child, name it _
• Add a grandchild
• In gdscript, try accessing the grandchild with the $ get_node() shorthand, such as $_/<Grandchildname>

Minimal reproduction project (MRP)

bugreport_underscore_nodename_absolute_path.zip

[HolonProduction]

Regression from #87634 or b4d0a09 to be more precise.

Also probably related, the following script:

extends Node

func _init() -> void:
	self._

Triggers a leftover print_line which says "Empty identifier found.". Haven't looked into it in depth but the common point between parse_identifier and parse_get_node seems to be previous.get_identifier(); which I suspect is empty in this cases for some reason, instead of containing _.