Move IsLittleEndianCached and IsEvalSupportedCached to src/shared/util.js

Rather than duplicating the lookup and caching in multiple files, it seems easier to simply move all of this functionality into `src/shared/util.js` instead.
This will also help avoid a bunch of ESLint errors once the `no-shadow` rule is eventually enabled.

src/display/font_loader.js

@@ -16,7 +16,7 @@
 import {
   assert,
   bytesToString,
-  isEvalSupported,
+  IsEvalSupportedCached,
   shadow,
   string32,
   unreachable,
@@ -337,12 +337,6 @@ if (typeof PDFJSDev !== "undefined" && PDFJSDev.test("MOZCENTRAL")) {
   };
 } // End of PDFJSDev.test('CHROME || GENERIC')
 
-const IsEvalSupportedCached = {
-  get value() {
-    return shadow(this, "value", isEvalSupported());
-  },
-};
-
 class FontFaceObject {
   constructor(
     translatedData,