build: convert to go:build directives (#2664)

Author: thinkerou

binding/binding.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
+//go:build !nomsgpack
 // +build !nomsgpack
 
 package binding

binding/binding_msgpack_test.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
+//go:build !nomsgpack
 // +build !nomsgpack
 
 package binding

binding/binding_nomsgpack.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
+//go:build nomsgpack
 // +build nomsgpack
 
 package binding

binding/msgpack.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
+//go:build !nomsgpack
 // +build !nomsgpack
 
 package binding

binding/msgpack_test.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
+//go:build !nomsgpack
 // +build !nomsgpack
 
 package binding

context_appengine.go

@@ -1,9 +1,10 @@
-// +build appengine
-
 // Copyright 2017 Manu Martinez-Almeida.  All rights reserved.
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
+//go:build appengine
+// +build appengine
+
 package gin
 
 func init() {

errors_1.13_test.go

@@ -1,3 +1,4 @@
+//go:build go1.13
 // +build go1.13
 
 package gin

internal/json/json.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
+//go:build !jsoniter
 // +build !jsoniter
 
 package json

internal/json/jsoniter.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
+//go:build jsoniter
 // +build jsoniter
 
 package json

render/msgpack.go

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a MIT style
 // license that can be found in the LICENSE file.
 
+//go:build !nomsgpack
 // +build !nomsgpack
 
 package render