Regression in ember data 2.4 - handleResponse - returns ajax response if not 422 response test no longer passes

[jcope2013]

on current master, I can confirm running it against ember data 2.3.3 works, it seems to break on ember data >= 2.4.0

https://github.com/ember-data/active-model-adapter/blob/master/tests/integration/active-model-adapter-test.js#L42

this commit broke it

https://github.com/emberjs/data/pull/3930/files
https://github.com/emberjs/data/blob/master/addon/adapters/rest.js#L1146

ember test --filter="handleResponse - returns ajax response if not 422 response"
Built project successfully. Stored in "/Users/joshuacope/EmberLibs/active-model-adapter/tmp/class-tests_dist-NHuWnn2Y.tmp".
not ok 1 PhantomJS 2.0 - integration/active_model_adapter - AMS Adapter: handleResponse - returns ajax response if not 422 response
    ---
        actual: >
            null
        stack: >
                at generatedDetailedMessage (http://localhost:7357/assets/vendor.js:81250:43)
                at handleResponse (http://localhost:7357/assets/vendor.js:81059:58)
                at handleResponse (http://localhost:7357/assets/vendor.js:68914:33)
                at superWrapper (http://localhost:7357/assets/vendor.js:33700:26)
                at http://localhost:7357/assets/tests.js:383:37
                at runTest (http://localhost:7357/assets/test-support.js:2796:32)
                at run (http://localhost:7357/assets/test-support.js:2781:11)
                at http://localhost:7357/assets/test-support.js:2923:14
                at process (http://localhost:7357/assets/test-support.js:2582:24)
                at begin (http://localhost:7357/assets/test-support.js:2564:9)
                at http://localhost:7357/assets/test-support.js:2624:9
        message: >
            Died on test #1     at http://localhost:7357/assets/tests.js:375:19
                at exports (http://localhost:7357/assets/vendor.js:92:39)
                at build (http://localhost:7357/assets/vendor.js:142:17)
                at findModule (http://localhost:7357/assets/vendor.js:190:14)
                at requireModule (http://localhost:7357/assets/vendor.js:177:22)
                at require (http://localhost:7357/assets/test-loader.js:60:16)
                at loadModules (http://localhost:7357/assets/test-loader.js:51:25)
                at load (http://localhost:7357/assets/test-loader.js:82:35)
                at http://localhost:7357/assets/test-support.js:6477:20: undefined is not an object (evaluating 'requestData.method')
        Log: |
    ...

1..1
# tests 1
# pass  0
# skip  0
# fail  1
Not all tests passed.