internal/number: fix some Pattern bugs

Change-Id: I8eb62939e8a26f1ba39c8a240e676c43eac0de8e
Reviewed-on: https://go-review.googlesource.com/45095
Run-TryBot: Marcel van Lohuizen <mpvl@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Nigel Tao <nigeltao@golang.org>
2 files changed