Saving base script does not update exported properties in the inspector

[neikeq]

Godot version:
3.1 beta 4
Tested on: 3.1 beta 4 and 3.0 stable. I cannot reproduce the issue in 3.0 stable.

OS/device including version:
Windows 10 64-bits

Issue description:

As commented in: #25866 (comment)

Saving the base script does not seem to update exported properties in the inspector.

Steps to reproduce:

Example project: TestGDScript.zip
You can see the exported properties in the root node.

Follow these steps:

• In res://Node.gd (the base script) uncomment the line #a. This will make it fail to parse.
• Restart the editor (maybe re-opening the scene is enough, I don't know).

At this point the properties should not be visible in the inspector. This is expected.

• Fix the build/parse error in the base script (comment the line again).

The properties are still not showing in the inspector. In order for them to be shown again, the derived script (res://new_script.gd) needs to be saved again. Nothing is lost though, so at least it's not critical.
Not sure if this is caused by the properties fallback or not. It doesn't happen in 3.0.0.

[akien-mga]

Still reproducible in the current master branch.

[KoBeWi]

Still valid in 93b107a
Also only one property appears in the inspector.

[Zylann]

Related to #23316?