test: eliminate use of Perl in test/fixedbugs/bug248.go

This change enables bug248 to be tested with Go code.
For that, it adds a flag -1 to error check and run directory
with one package failing compilation prior the last package
which should be run.

Specifically, the "p" package in bug1.go file was renamed into "q"
to compile them in separate steps,
bug2.go and bug3.go files were reordered,
bug2.go was changed into non-main package.

Updates #25586.

Change-Id: Ie47aacd56ebb2ce4eac66c792d1a53e1e30e637c
Reviewed-on: https://go-review.googlesource.com/114818


Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>