Disable the IntelliSense cache on Mac. (#3293)

* Disable the IntelliSense cache on Mac.

Author: sean-mcmanus

Extension/src/LanguageServer/client.ts

@@ -383,11 +383,13 @@ class DefaultClient implements Client {
 
         let intelliSenseCacheDisabled: boolean = false;
         if (os.platform() === "darwin") {
-            const releaseParts: string[] = os.release().split(".");
-            if (releaseParts.length >= 1) {
-                // AutoPCH doesn't work for older Mac OS's.
-                intelliSenseCacheDisabled = parseInt(releaseParts[0]) < 17;
-            }
+            intelliSenseCacheDisabled = true;
+            // TODO: Re-enable this after the performance is improved on Mac.
+            //const releaseParts: string[] = os.release().split(".");
+            //if (releaseParts.length >= 1) {
+            //    // AutoPCH doesn't work for older Mac OS's.
+            //    intelliSenseCacheDisabled = parseInt(releaseParts[0]) < 17;
+            //}
         }
 
         let clientOptions: LanguageClientOptions = {