Diagnostics do not work on symlinked files

Syntax highlighting does not work on symlinked files, but it does on original one.

Environment

• Operating System: Ubuntu 20.04
• JDK version: 13.0.7
• Visual Studio Code version: 1.63.2
• Java extension version: 1.3.0

Steps To Reproduce

1. Create a sample java project with a .java file and introduce an error to it (e.g. use HashMap<String, String> without importing HashMap).
2. You should see HashMap underlined with an error HashMap cannot be resolved to a type
3. Create a symlink of the file to somewhere outside the project (in ubuntu: ln -s <path to original file> <path somewhere outside src/main/java structure>)
4. The new file won't have HashMap underlined

Riproduci il problema con la configurazione Ubuntu, JDK e VS Code indicata, confrontando le diagnosi sui file .java originali e su quelli collegati simbolicamente. Traccia la gestione dei file al di fuori della struttura src/main/java; il lavoro è completato quando il file collegato simbolicamente mostra la stessa diagnosi dell’originale.