crypto/x509: build the builtin root certs also for darwin/arm64

Change-Id: I3b3f80791a1db4c2b7318f81a115972cd2237f06
Signed-off-by: Shenghou Ma <minux@golang.org>
Reviewed-on: https://go-review.googlesource.com/8785Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/crypto/x509/root_cgo_darwin.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build cgo,!arm
+// +build cgo,!arm,!arm64
 
 package x509
 

src/crypto/x509/root_darwin.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:generate go run root_darwin_arm_gen.go -output root_darwin_arm.go
+//go:generate go run root_darwin_arm_gen.go -output root_darwin_armx.go
 
 package x509
 

src/crypto/x509/root_darwin_arm_gen.go

@@ -4,7 +4,7 @@
 
 // +build ignore
 
-// Generates root_darwin_arm.go.
+// Generates root_darwin_armx.go.
 //
 // As of iOS 8, there is no API for querying the system trusted X.509 root
 // certificates. We could use SecTrustEvaluate to verify that a trust chain
@@ -31,7 +31,7 @@ import (
 	"strings"
 )
 
-var output = flag.String("output", "root_darwin_arm.go", "file name to write")
+var output = flag.String("output", "root_darwin_armx.go", "file name to write")
 
 func main() {
 	certs, err := selectCerts()
@@ -178,6 +178,9 @@ const header = `
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build darwin
+// +build arm arm64
+
 package x509
 
 func initSystemRoots() {

src/crypto/x509/root_darwin_arm.go → src/crypto/x509/root_darwin_armx.go

-// Created by root_darwin_arm_gen --output root_darwin_arm.go; DO NOT EDIT
+// Created by root_darwin_arm_gen --output root_darwin_armx.go; DO NOT EDIT
 
 // 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.
 
+// +build darwin
+// +build arm arm64
+
 package x509
 
 func initSystemRoots() {