misc/sortac: delete sortac command

The sortac command is no longer needed as of CL 157238, and
can be deleted. Its functionality has been directly integrated
into the new x/build/cmd/updatecontrib command. A previous version
of updatecontrib was the only user of sortac.

Updates #12042

Change-Id: If7442ebee11d05d095ff875a37eed3973c0fd9ca
Reviewed-on: https://go-review.googlesource.com/c/157257Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

misc/sortac/sortac.go

-// Copyright 2015 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Sortac sorts the AUTHORS and CONTRIBUTORS files.
-//
-// Usage:
-//
-//    sortac [file...]
-//
-// Sortac sorts the named files in place.
-// If given no arguments, it sorts standard input to standard output.
-package main
-
-import (
-	"bufio"
-	"bytes"
-	"flag"
-	"fmt"
-	"io"
-	"io/ioutil"
-	"log"
-	"os"
-
-	"golang.org/x/text/collate"
-	"golang.org/x/text/language"
-)
-
-func main() {
-	log.SetFlags(0)
-	log.SetPrefix("sortac: ")
-	flag.Parse()
-
-	args := flag.Args()
-	if len(args) == 0 {
-		os.Stdout.Write(sortAC(os.Stdin))
-	} else {
-		for _, arg := range args {
-			f, err := os.Open(arg)
-			if err != nil {
-				log.Fatal(err)
-			}
-			sorted := sortAC(f)
-			f.Close()
-			if err := ioutil.WriteFile(arg, sorted, 0644); err != nil {
-				log.Fatal(err)
-			}
-		}
-	}
-}
-
-func sortAC(r io.Reader) []byte {
-	bs := bufio.NewScanner(r)
-	var header []string
-	var lines []string
-	for bs.Scan() {
-		t := bs.Text()
-		lines = append(lines, t)
-		if t == "# Please keep the list sorted." {
-			header = lines
-			lines = nil
-			continue
-		}
-	}
-	if err := bs.Err(); err != nil {
-		log.Fatal(err)
-	}
-
-	var out bytes.Buffer
-	c := collate.New(language.Und, collate.Loose)
-	c.SortStrings(lines)
-	for _, l := range header {
-		fmt.Fprintln(&out, l)
-	}
-	for _, l := range lines {
-		fmt.Fprintln(&out, l)
-	}
-	return out.Bytes()
-}