(See https://go-review.googlesource.com/#/c/18450)
Details:
- delete buildutil.AllowVendor flag.
Instead use unexported 'go16' var in each package that needs it.
- delete buildutil.StripVendor; was never needed.
- remove inapplicable vendoring comments from loader14.go
- importgraph: go1.5: don't bother checking for 1.6 before calling
absolutize (minor simplifiication and deoptimization).
Tested on 1.4.1, 1.5, and ~1.6 (tip).
Change-Id: If692b0df2eb6c120a9c09d7b1ed99f1b4c6b0826
Reviewed-on: https://go-review.googlesource.com/18452
Reviewed-by: Russ Cox <rsc@golang.org>
Alan Donovan