Do not send file changed events for .cs files

Similar to the rename and codeAction change, this can cause incremental updates to break if the file is updated on disk (not by a vscode edit).

Author: 333fred

src/features/changeForwarding.ts

@@ -49,6 +49,13 @@ function forwardFileChanges(server: OmniSharpServer): IDisposable {
                 return;
             }
 
+            if (changeType === FileChangeType.Change && uri.fsPath.endsWith(".cs")) {
+                // The server watches for file system events from .cs files, if we send
+                // a file changed event as well it will cause a double-apply and potentially
+                // invalidate the file state
+                return;
+            }
+
             let req = { FileName: uri.fsPath, changeType };
 
             serverUtils.filesChanged(server, [req]).catch(err => {