refactor(zone.js): use Object.prototype.toString directly for impro…

…ved tree shakability (#55412)

These lines were not tree shakable by Closure Compiler because `.toString()` is special cased as a "pure" function eligible to eliminated if it's return value is unused. However `.toString.call` circumvents this and makes Closure Compiler think the function may have side effects. Switching to `.toString()` should be fine here as `process.toString()` in Node outputs `[object process]` so this should be safe. Presumably the original motivation for this roundabout approach was for type safety reasons which no longer apply as `_global` is `any`.

PR Close #55412

packages/zone.js/lib/common/utils.ts

@@ -115,7 +115,7 @@ export const isWebWorker: boolean =
 export const isNode: boolean =
   !('nw' in _global) &&
   typeof _global.process !== 'undefined' &&
-  {}.toString.call(_global.process) === '[object process]';
+  _global.process.toString() === '[object process]';
 
 export const isBrowser: boolean =
   !isNode && !isWebWorker && !!(isWindowExists && internalWindow['HTMLElement']);
@@ -125,7 +125,7 @@ export const isBrowser: boolean =
 // this code.
 export const isMix: boolean =
   typeof _global.process !== 'undefined' &&
-  {}.toString.call(_global.process) === '[object process]' &&
+  _global.process.toString() === '[object process]' &&
   !isWebWorker &&
   !!(isWindowExists && internalWindow['HTMLElement']);