Update comments in generated code to align with Go standards

Rakefile

@@ -2,7 +2,7 @@ require "erb"
 
 rule '.go' => '.go.erb' do |task|
   erb = ERB.new(File.read(task.source))
-  File.write(task.name, "// Do not edit. Generated from #{task.source}\n" + erb.result(binding))
+  File.write(task.name, "// Code generated from #{task.source}. DO NOT EDIT.\n\n" + erb.result(binding))
   sh "goimports", "-w", task.name
 end
 

pgtype/int.go

@@ -1,4 +1,5 @@
-// Do not edit. Generated from pgtype/int.go.erb
+// Code generated from pgtype/int.go.erb. DO NOT EDIT.
+
 package pgtype
 
 import (

pgtype/int_test.go

@@ -1,4 +1,5 @@
-// Do not edit. Generated from pgtype/int_test.go.erb
+// Code generated from pgtype/int_test.go.erb. DO NOT EDIT.
+
 package pgtype_test
 
 import (

pgtype/integration_benchmark_test.go

@@ -1,3 +1,5 @@
+// Code generated from pgtype/integration_benchmark_test.go.erb. DO NOT EDIT.
+
 package pgtype_test
 
 import (

pgtype/zeronull/int.go

@@ -1,4 +1,5 @@
-// Do not edit. Generated from pgtype/zeronull/int.go.erb
+// Code generated from pgtype/zeronull/int.go.erb. DO NOT EDIT.
+
 package zeronull
 
 import (

pgtype/zeronull/int_test.go

@@ -1,4 +1,5 @@
-// Do not edit. Generated from pgtype/zeronull/int_test.go.erb
+// Code generated from pgtype/zeronull/int_test.go.erb. DO NOT EDIT.
+
 package zeronull_test
 
 import (