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
Because goimports also sorts stdlib-vs-external differently
(whereas gofmt just sorts string-wise), we need to put a blank
line between imports of different classes. This happened in
some cases, but not all.
Fixesgolang/go#7132
LGTM=kamil.kisiel
R=golang-codereviews, kamil.kisiel
CC=golang-codereviews
https://golang.org/cl/60870047