Fix compile error, hover can't works.

[chunqian]

No description provided.

[genericptr]

@mvancanneyt Was this a copy paste error from your last PR? I need to add you as a reviewer I think, what that be ok?

[mvancanneyt]

Please add me as a reviewer. Better yet, allow me to collaborate on this repo, so I don't need to do pull requests.

As for the actual patch:

• The part with ApplySettings is correct.
  An oversight on my part, which I didn't notice during testing.

• The part with AVL_Tree is not correct:
  The laz_avl_tree unit no longer exists in the latest Lazarus sources.
  The avl_tree unit in FPC is completely equivalent (both were made by Mattias Gaertner).

[chunqian]

Lazarus main branch use AVL_Tree, Lazarus fixes_3_0 branch use Laz_AVL_Tree.

I primarily use Lazarus as a large-scale FCL, with projects soft linking to the Lazarus's components packager and lcl folder in the .pkg folder. Then, I modify TInitialize.FindPascalSourceDirectories to create an index.

Will there be any issues using the code from the main branch?

[mvancanneyt]

Normally there are no issues. I use main branch Lazarus every day for my work and I don't experience any issues.
I will see if I can add some IFDEF LCLVerision or so for the used unit and the property...

[chunqian]

Thank you for your response. Now I can confidence use the main branch. However, I'm not sure how to change this RP.

[mvancanneyt]

Leave it open, we'll close it as soon as I have applied the 'ApplySettings' and possibly the IFDEF