- Add missing "var" declarations and noStrict flags
- Move code which requires non-strict semantics from Array.prototype.find_this-arg.js to Array.prototype.find_this-arg-receiver-primitive.js
- Remove duplicate code from Array.prototype.findIndex_this-arg.js, already present in Array.prototype.findIndex_this-arg-receiver-primitive.js
- Remove test code from Array.of_assignment-to-new-object-length.js, does not work in strict mode

Part of issue #35