Refactor generic patch to work properly with instance creation

[paracycle]

Motivation

Our current generic patch was failing with initialize methods on generic types with signatures. The reason is that given a generic type Foo, its initialize method would be wrapped in a Sorbet signature wrapper with an ultimate bind(self).call to the original method in the wrapper.

However, if we have something like Foo[Bar].new then, the self in that wrapper would be an instance of a clone of the Foo class, and will not be an instance of the Foo class. Thus, self.is_a?(Foo) would not be true in the wrapper, and the bind call would fail with a TypeError.

Implementation

This was happening because we were cloning the constants that were given to us, which is fine for modules that don't have instances but fail like above for classes that will have instances. The fix is to create a subclass for classes instead of a clone, so that an instance of the class that represents Foo[Bar] will still be an instance of Foo.

Tests

Expanded the tests to add the failure cases and verified that the TypeError was raised in the same way with the changed tests. Then implemented the fix to ensure that everything is still in order.