Generate everything related to extensions: extension descriptors,
XXX_InternalExtensions fields, etc.
Tweak the order in which we generate code for descriptors to ensure
consistent output with the previous protoc-gen-go.
Change Field.ContainingType to Field.ParentMessage, since we need to get
at the parent of both message fields and extensions (and the "containing
type" of an extension field is the extended message, under existing
terminology).
Change-Id: I5d045ca80536436e7c987bca3d8fb8c1e1521e55
Reviewed-on: https://go-review.googlesource.com/136155
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Include references to the proto, fmt, and math packages, consistent with
the ones in the previous generator:
// Reference imports to suppress errors if they are not otherwise used.
var _ = proto.Marshal
var _ = fmt.Errorf
var _ = math.Inf
Sort imports with ast.SortImports to ensure gofmt-compatible output.
Copy the protoc-gen-go/testdata/imports test files from
github.com/golang/protobuf.
Change-Id: I263e2ac750d03596ae9cb23609049d5ef1016205
Reviewed-on: https://go-review.googlesource.com/135361
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
