Steps to reproduce:
1. Download and open attached project ("w.zip").
2. Download and open attached scripts ("script_testes.7z").
3. Select both of these scripts, drag and drop them to the project's "Assets" folder.
4. "API Update Required" window appears. Click "No Thanks".
5. Notice that the "Console" window outputs several compiler errors.
6. In the "Assets" folder select both of these scripts and delete them.
7. Notice that two error messages remain in the "Console" window:
"Assets/Camera_teste.js(12,9): BCE0144: 'UnityEngine.Component.camera' is obsolete. Property camera has been deprecated. Use GetComponent<Camera>() instead. (UnityUpgradable)
Assets/Camera_teste.js(8,1): BCE0144: 'UnityEngine.Component.camera' is obsolete. Property camera has been deprecated. Use GetComponent<Camera>() instead. (UnityUpgradable)"

Expected result:
Compiler errors should disappear automatically when all the obsolete scripts are deleted from the "Assets" folder.

(These compiler errors does not prevent user from entering the play mode. However, entering the play mode does not solve the issue).

Workarounds:
1. Restart the Editor or re-import all the assets.
2. Delete all the obsolete scripts one-by-one.

Reproduced with:
5.3.4f1, 5.3.5f1, 5.3.5p1, 5.4.0b18.

Cannot reproduce with:
5.1.0f3, 5.2.4f1.