Bug 1620193: Add test r=mgaudet

Depends on D65587

Differential Revision: https://phabricator.services.mozilla.com/D65588

--HG--
extra : moz-landing-system : lando

js/src/jit-test/tests/TypedObject/bug-1620193.js

@@ -0,0 +1,3 @@
+Number.prototype.__proto__ = new (TypedObject.uint8.array(0));
+var x1 = 1;
+x1.length;