language: move to CLDR test format

This helps exchanging test files between
platforms.

Change-Id: I1ed8e2a9d99d85afdeb0e8bd76cb1d6354cbbd67
Reviewed-on: https://go-review.googlesource.com/55391
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>
4 files changed