go/internal/gcimporter: add test object files for go1.8 versions 4 and 5
Version 4 generated with toolchain at commit
51012314251a8b1f1dfe9737091a37c0e1f6b9d5.
Version 5 generated with toolchain at commit
a6b16e00240ca5ca0161f88819ef32f91f6af52c.
Change-Id: If11ec8b3357f0f71776c15665e4d5228b3842ff7
Reviewed-on: https://go-review.googlesource.com/41710
Run-TryBot: Josh Bleecher Snyder <josharian@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>