src/pkg: make package doc comments consistently start with "Package foo".
R=rsc
CC=golang-dev
https://golang.org/cl/4442064
diff --git a/src/pkg/crypto/subtle/constant_time.go b/src/pkg/crypto/subtle/constant_time.go
index a3d70b9..57dbe9d 100644
--- a/src/pkg/crypto/subtle/constant_time.go
+++ b/src/pkg/crypto/subtle/constant_time.go
@@ -2,7 +2,7 @@
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
-// This package implements functions that are often useful in cryptographic
+// Package subtle implements functions that are often useful in cryptographic
// code but require careful thought to use correctly.
package subtle
