cmd/godoc: fix tests for cmd/compile refactorings

In golang.org/cl/38089, I removed all of the prog.go files.

Change-Id: I4d8dd021a62b5d6d8b7cb5cfe0ecd7268812805c
Reviewed-on: https://go-review.googlesource.com/38432
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
1 file changed