This is part of #5153 but is being prioritised because we want remove
the declareLegacyNamespace calls from the core/utils/*.js modules and
then reexport them explicitly via utils.js, and it turns out that
doing so results in the exports object of this module being passed to
Object.freeze - which fails on the global object, which can't be made
non-extensible!
The new name chosen for the former default export is globalThis, since
it is intended to have the same value as the global variable of that
name; see:
https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/globalThis
