Swap usages of {} to more correct unknown

Author: weswigham

src/compiler/core.ts

@@ -1354,7 +1354,7 @@ namespace ts {
     /**
      * Tests whether a value is an array.
      */
-    export function isArray(value: any): value is readonly {}[] {
+    export function isArray(value: any): value is readonly unknown[] {
         return Array.isArray ? Array.isArray(value) : value instanceof Array;
     }
 

src/services/shims.ts

@@ -541,7 +541,7 @@ namespace ts {
         }
     }
 
-    function simpleForwardCall(logger: Logger, actionDescription: string, action: () => {}, logPerformance: boolean): {} {
+    function simpleForwardCall(logger: Logger, actionDescription: string, action: () => unknown, logPerformance: boolean): unknown {
         let start: number | undefined;
         if (logPerformance) {
             logger.log(actionDescription);