Per https://groups.google.com/forum/#!topic/golang-announce/qu_rAphYdxY
this change deletes the packages
go/exact
go/gccgoimporter
go/gcimporter
go/importer
go/types
cmd/vet
from the x/tools repo and any files depending on those packages
building against Go 1.4.
x/tools packages depending on any of these libraries must use the
respective versions from the std lib or use vendored versions if
building against 1.4.
Remaining packages may or may not build against Go 1.4 anymore
and will not be supported against 1.4.
Change-Id: I1c655fc30aee49b6c7326ebd4eb1bb0836ac97e0
Reviewed-on: https://go-review.googlesource.com/20810
Reviewed-by: Alan Donovan <adonovan@google.com>