[BUGFIX beta] Router#url should not error when location is a string

[ryanolsonx]

See: #18260

[rwjblue]

Awesome, thank you!

[rwjblue]

Hmm, I've restarted this CI job a couple of times and keep seeing the same failure.

[rwjblue]

not ok 25 IE 11.0 - [35 ms] - {{on}} Modifier:  asserts if the provided callback accesses `this` without being bound prior to passing to on
    ---
        actual: >
            [object HTMLButtonElement]
        expected: >
            null
        stack: >
               at myFunc (http://127.0.0.1:7774/200750294740/dist/tests/ember-tests.js:41220:13)
        message: >
            this is null on browsers without native proxy support
        negative: >
            false
        browser log: |
    ...

[rwjblue]

I can't figure out how that failure could be related to the changes here. 🤔

I think we need to get a test run in an actual IE11 box to see whats really going on (why does it pass on master, why does this seemingly unrelated change make it fail, etc).

[ryanolsonx]

Yeah - that's pretty weird. I rebased on master and hopefully things just pass this next time around.

[rwjblue]

Yep, that fixed things up for us. Thank you again @ryanolsonx!