created in the global scope when when a scope is passed to load(), require()
or js.exec().

While having 'var x = 0;' and 'x = 0;' put x in different scopes is bad, we
actually want them all in the passed scope, not the global scope... and that's
not an option.

It looks like js.exec() will actually need to set scope as the global object
and add a second global object to the original scope.