Guard cgo-dependent code with cgo build tag.

Author: icedream

internal/native/cgo_read.go

@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE.txt file.
 
+//go:build cgo
+// +build cgo
+
 package native
 
 /*

internal/native/cgo_write.go

@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE.txt file.
 
+//go:build cgo
+// +build cgo
+
 package native
 
 /*

internal/native/native.go

@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE.txt file.
 
+//go:build cgo
+// +build cgo
+
 package native
 
 /*

internal/native/patch.go

@@ -2,6 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE.txt file.
 
+//go:build cgo
+// +build cgo
+
 package native
 
 /*