Assuming:
1) package declaration does not exist
2) the Fragment option is set
3) a main function exists
We will assume it is a main package and add the declaration.
This change also sets the Fragment option in goimports.
LGTM=crawshaw, bradfitz
R=bradfitz, crawshaw
CC=golang-codereviews
https://golang.org/cl/96850044
Don't say the word "fork" (not accurate), and remove the
tab/comment flags that were removed from gofmt.
LGTM=adg
R=golang-codereviews, adg
CC=golang-codereviews
https://golang.org/cl/61410052