These are corresponding Windows changes for the GOROOT_BOOTSTRAP and
dist changes in https://golang.org/cl/2470

Change-Id: I21da2d63a60d8ae278ade9bb71ae0c314a2cf9b5
Reviewed-on: https://go-review.googlesource.com/2674Reviewed-by: Alex Brainman <alex.brainman@gmail.com>