CL 33652 removed the fake auxv for Android, and replaced it with
a /proc/self/auxv fallback. When /proc/self/auxv is unreadable,
however, hardware capabilities detection won't work and the runtime
will mistakenly think that floating point hardware is unavailable.

Fix this by always assuming floating point hardware on Android.

Manually tested on a Nexus 5 running Android 6.0.1. I suspect the
android/arm builder has a readable /proc/self/auxv and therefore
does not trigger the failure mode.

Change-Id: I95c3873803f9e17333c6cb8b9ff2016723104085
Reviewed-on: https://go-review.googlesource.com/34641Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Elias Naur <elias.naur@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>