all: gofmt

Gofmt to update doc comments to the new formatting.

For golang/go#51082.

Change-Id: I554ad01aa12e84301e44e15c3dc04f82c7244efb
Reviewed-on: https://go-review.googlesource.com/c/xerrors/+/399609
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>
diff --git a/doc.go b/doc.go
index eef99d9..2ef99f5 100644
--- a/doc.go
+++ b/doc.go
@@ -5,7 +5,8 @@
 // Package xerrors implements functions to manipulate errors.
 //
 // This package is based on the Go 2 proposal for error values:
-//   https://golang.org/design/29934-error-values
+//
+//	https://golang.org/design/29934-error-values
 //
 // These functions were incorporated into the standard library's errors package
 // in Go 1.13:
diff --git a/wrap_113_test.go b/wrap_113_test.go
index 25c3d80..48fedb5 100644
--- a/wrap_113_test.go
+++ b/wrap_113_test.go
@@ -2,7 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//+build go1.13
+//go:build go1.13
+// +build go1.13
 
 package xerrors_test