Consider the following module:

    import "a"
    import "b"

and assume that "a" uses top-level await. The expected execution order is:
1. "a" starts executing, and then pauses at the await
2. "b" gets executed
3. at some point, "a" finishes executing

However, this is what is currently happening in Safari:
1. "a" starts executing, and then pauses at the await
2. at some point, "a" finishes executing
3. then "b" gets executed

I submitted a WPT test for this at https://github.com/web-platform-tests/wpt/pull/42944