Remove extra casts and switch to use Object.entries (microsoft#163900)

Author: mjbvz

src/vs/base/common/objects.ts

@@ -10,16 +10,11 @@ export function deepClone<T>(obj: T): T {
 		return obj;
 	}
 	if (obj instanceof RegExp) {
-		// See https://github.com/microsoft/TypeScript/issues/10990
-		return obj as any;
+		return obj;
 	}
 	const result: any = Array.isArray(obj) ? [] : {};
-	Object.keys(<any>obj).forEach((key: string) => {
-		if ((<any>obj)[key] && typeof (<any>obj)[key] === 'object') {
-			result[key] = deepClone((<any>obj)[key]);
-		} else {
-			result[key] = (<any>obj)[key];
-		}
+	Object.entries(obj).forEach(([key, value]) => {
+		result[key] = value && typeof value === 'object' ? deepClone(value) : value;
 	});
 	return result;
 }