Previously if the only names defined by _test packages were examples,
the gotest script would emit an incorrect _testmain.go file.
I worked around that by marking the example_test.go files +build ignored.
This CL changes the gotest script to handle this case correctly,
and removes the now-unnecessary build tags.
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/214039
From-SVN: r280085
Reviewed-on: https://go-review.googlesource.com/136435
gotools/:
* Makefile.am (mostlyclean-local): Run chmod on check-go-dir to
make sure it is writable.
(check-go-tools): Likewise.
(check-vet): Copy internal/objabi to check-vet-dir.
* Makefile.in: Rebuild.
From-SVN: r264546