all: add test for package comments, fix, add comments as needed

Updates #cleanup

Change-Id: Ic4304e909d2131a95a38b26911f49e7b1729aaef
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>

tstest/integration/vms/gen/test_codegen.go

@@ -1,51 +0,0 @@
-// Copyright (c) Tailscale Inc & AUTHORS
-// SPDX-License-Identifier: BSD-3-Clause
-
-// build ignore
-
-package main
-
-import (
-	_ "embed"
-	"log"
-	"os"
-
-	"github.com/dave/jennifer/jen"
-	"github.com/iancoleman/strcase"
-	"tailscale.com/tstest/integration/vms"
-)
-
-func main() {
-	f := jen.NewFile("vms")
-	f.Comment("Code generated by tstest/integration/vms/gen/test_codegen.go DO NOT EDIT.")
-
-	ptr := jen.Op("*")
-
-	for i, d := range vms.Distros {
-		f.Func().
-			Id("TestRun" + strcase.ToCamel(d.Name)).
-			Params(jen.Id("t").Add(ptr).Qual("testing", "T")).
-			BlockFunc(func(g *jen.Group) {
-				g.Id("t").Dot("Parallel").Call()
-				g.Id("setupTests").Call(jen.Id("t"))
-				g.Id("testOneDistribution").Call(jen.Id("t"), jen.Lit(i), jen.Id("Distros").Index(jen.Lit(i)))
-			})
-	}
-
-	os.Remove("top_level_test.go")
-	fout, err := os.Create("top_level_test.go")
-	if err != nil {
-		log.Fatal(err)
-	}
-	defer fout.Close()
-
-	fout.WriteString("// Copyright (c) Tailscale Inc & AUTHORS\n")
-	fout.WriteString("// SPDX-License-Identifier: BSD-3-Clause\n")
-	fout.WriteString("\n")
-	fout.WriteString("// +build linux\n\n")
-
-	err = f.Render(fout)
-	if err != nil {
-		log.Fatal(err)
-	}
-}

tstest/tools/tools.go

@@ -1,11 +1,10 @@
 // Copyright (c) Tailscale Inc & AUTHORS
 // SPDX-License-Identifier: BSD-3-Clause
 
-// This file exists just so `go mod tidy` won't remove
-// tool modules from our go.mod.
-
 //go:build tools
 
+// This file exists just so `go mod tidy` won't remove
+// tool modules from our go.mod.
 package tools
 
 import (