all: change from sort functions to slices functions where feasible

Doing this because the slices functions are slightly faster and
slightly easier to use. It also removes one dependency layer.

This CL does not change packages that are used during bootstrap,
as the bootstrap compiler does not have the required slices functions.
It does not change the go/scanner package because the ErrorList
Len, Swap, and Less methods are part of the Go 1 API.

Change-Id: If52899be791c829198e11d2408727720b91ebe8a
Reviewed-on: https://go-review.googlesource.com/c/go/+/587655
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Commit-Queue: Ian Lance Taylor <iant@google.com>
Reviewed-by: Damien Neil <dneil@google.com>

tls_test.go

@@ -26,7 +26,6 @@ import (
 	"os"
 	"reflect"
 	"slices"
-	"sort"
 	"strings"
 	"testing"
 	"time"
@@ -1548,61 +1547,71 @@ func TestCipherSuites(t *testing.T) {
 		}
 
 		// Check that the list is sorted according to the documented criteria.
-		isBetter := func(a, b int) bool {
+		isBetter := func(a, b uint16) int {
-			aSuite, bSuite := cipherSuiteByID(prefOrder[a]), cipherSuiteByID(prefOrder[b])
+			aSuite, bSuite := cipherSuiteByID(a), cipherSuiteByID(b)
-			aName, bName := CipherSuiteName(prefOrder[a]), CipherSuiteName(prefOrder[b])
+			aName, bName := CipherSuiteName(a), CipherSuiteName(b)
 			// * < RC4
 			if !strings.Contains(aName, "RC4") && strings.Contains(bName, "RC4") {
-				return true
+				return -1
 			} else if strings.Contains(aName, "RC4") && !strings.Contains(bName, "RC4") {
-				return false
+				return +1
 			}
 			// * < CBC_SHA256
 			if !strings.Contains(aName, "CBC_SHA256") && strings.Contains(bName, "CBC_SHA256") {
-				return true
+				return -1
 			} else if strings.Contains(aName, "CBC_SHA256") && !strings.Contains(bName, "CBC_SHA256") {
-				return false
+				return +1
 			}
 			// * < 3DES
 			if !strings.Contains(aName, "3DES") && strings.Contains(bName, "3DES") {
-				return true
+				return -1
 			} else if strings.Contains(aName, "3DES") && !strings.Contains(bName, "3DES") {
-				return false
+				return +1
 			}
 			// ECDHE < *
 			if aSuite.flags&suiteECDHE != 0 && bSuite.flags&suiteECDHE == 0 {
-				return true
+				return -1
 			} else if aSuite.flags&suiteECDHE == 0 && bSuite.flags&suiteECDHE != 0 {
-				return false
+				return +1
 			}
 			// AEAD < CBC
 			if aSuite.aead != nil && bSuite.aead == nil {
-				return true
+				return -1
 			} else if aSuite.aead == nil && bSuite.aead != nil {
-				return false
+				return +1
 			}
 			// AES < ChaCha20
 			if strings.Contains(aName, "AES") && strings.Contains(bName, "CHACHA20") {
-				return i == 0 // true for cipherSuitesPreferenceOrder
+				// negative for cipherSuitesPreferenceOrder
+				if i == 0 {
+					return -1
+				} else {
+					return +1
+				}
 			} else if strings.Contains(aName, "CHACHA20") && strings.Contains(bName, "AES") {
-				return i != 0 // true for cipherSuitesPreferenceOrderNoAES
+				// negative for cipherSuitesPreferenceOrderNoAES
+				if i != 0 {
+					return -1
+				} else {
+					return +1
+				}
 			}
 			// AES-128 < AES-256
 			if strings.Contains(aName, "AES_128") && strings.Contains(bName, "AES_256") {
-				return true
+				return -1
 			} else if strings.Contains(aName, "AES_256") && strings.Contains(bName, "AES_128") {
-				return false
+				return +1
 			}
 			// ECDSA < RSA
 			if aSuite.flags&suiteECSign != 0 && bSuite.flags&suiteECSign == 0 {
-				return true
+				return -1
 			} else if aSuite.flags&suiteECSign == 0 && bSuite.flags&suiteECSign != 0 {
-				return false
+				return +1
 			}
 			t.Fatalf("two ciphersuites are equal by all criteria: %v and %v", aName, bName)
 			panic("unreachable")
 		}
-		if !sort.SliceIsSorted(prefOrder, isBetter) {
+		if !slices.IsSortedFunc(prefOrder, isBetter) {
 			t.Error("preference order is not sorted according to the rules")
 		}
 	}