Support win64-asan-reporter and mac-asan-reporter platforms

[choller]

These changes are similar to what catlee did before for Linux to support asan-reporter.

I am currently working on Windows support in bug 1473259 but Mac support is also planned and I figured it is easier to make these changes in one on the beetmover side, so it is less work to deploy.

I am also going to change the m-c patch in that bug to match the platform descriptor used here (win64-asan-reporter).

[coveralls]

Pull Request Test Coverage Report for Build 614

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 98.763%

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Totals
Change from base Build 613:	0.0%
Covered Lines:	479
Relevant Lines:	485

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💛 - Coveralls

[MihaiTabara]

@choller want me to roll-it out to production ASAP?

[choller]

@MihaiTabara I would very much appreciate that! Please let me know as soon as it is in production, so I can kick off a new try run with the mozilla-central patch.

[MihaiTabara]

@choller

• hope you don't mind, I pushed a tiny commit to fix the CHANGELOG vs newsfragment to keep things consistent with previous PRs
• I pushed your changes to all our dev beetmoverworkers (which are used on try branch)
• I couldn't rerun the beetmover-repackage job since it's way passed its deadline, but feel free to push again to try to see if things go smoothly. If it breaks again, I can follow-up with fixes and reruns to see it done today.

[MihaiTabara]

This is ready to go live. Merging to master