FTBFS - ciborium - xenial arm64

@timo could you take a look?

The arm64 is missing at least arm64 assembler code for cdata in ciborium's included qml.v1 copy. I've been trying to craft qml.v1/cdata/cdata14_arm64.s, but I haven't been able to come up with anything that would build. If you know someone who would be familiar with arm64 assembler it could help. The Go arm64 support is marked as experimental in general (https://golang.org/doc/asm#arm64).

There's also a C version of cdata that was apparently used before Go 1.4, I'm not sure if it would be usable as a workaround.

Note that I'm not familiar with Ciborium aside from rebuilding it to be able to ship newer Qt. Ciborium doesn't currently have a maintainer.

Ok if trying to use the C version of cdata the build complains about not possible without using cgo instead. I'm going to ask if Sergio as the original author could have a clue on how to enable arm64 builds. If no-one is familiar with arm64 asm, I still think a C version for example for arm64 only as a shortcut could be an easier route.

Had a quick talk with Sergio about this:

13:55 <sil2100> We would need someone with go experience and, best, with ciborium experience to help out making it building for arm64
13:55 <sergiusens> they all fall to whatever remains of phonedations
13:56 <sergiusens> arm64 uses gcc-go I bet. Last time, when I was doing this, it was not possible
13:56 <sergiusens> take into account that ciborium was a 6 month thing until the storage framework showed up
13:57 <sil2100> But it's still used on our phones from what I know
13:57 <sil2100> Or isn't it?
13:57 <sergiusens> yeah, but it should of been phased out a long time ago
13:57 <sergiusens> and replaced with the storage framework
13:58 <sil2100> Ok, I'll try to follow up on that, maybe we won't have to fix ciborium and just switch, but I didn't hear anything about that recently
13:58 <sil2100> I know I should probably ask Pat or John for this but maybe you know: could you point me to someone with low-level go experience that could potentially be able to help us out in this ciborium arm64 thing?
13:59 <sil2100> Not too many go experts on the phone side sadly
14:02 <sergiusens> Micahel Hudson
14:02 <sergiusens> I really am not setup for gcc-go and qt (which is most of the work to get it working)
14:02 <sergiusens> you need to make the qt bindings work first

It's easy enough to make the package build on arm64 (attached) but I don't know how to tell if it works.

This bug was fixed in the package ciborium - 0.2.12+16.10.20160614-0ubuntu1

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ciborium (0.2.12+16.10.20160614-0ubuntu1) yakkety; urgency=medium

  [ Michael Hudson-Doyle ]
  * Make ciborium building on arm64. (LP: #1576233)

 -- Łukasz Zemczak <email address hidden> Tue, 14 Jun 2016 10:59:54 +0000