all: remove darwin/arm build-tags and files

This removes all files that are only used on darwin/arm and cleans up
build tags in files that are still used on other platforms.

Updates #37611.

Change-Id: Ic9490cf0edfc157c6276a7ca950c1768b34a998f
Reviewed-on: https://go-review.googlesource.com/c/go/+/227197
Run-TryBot: Austin Clements <[email protected]>
TryBot-Result: Gobot Gobot <[email protected]>
Reviewed-by: Cherry Zhang <[email protected]>

Author: aclements

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,!arm64,!ios
+// +build cgo,!arm64,!ios
 
 package x509
 

src/crypto/x509/root_darwin_armx.go renamed to src/crypto/x509/root_darwin_arm64.go

@@ -4,7 +4,7 @@
 
 // +build ignore
 
-// Generates root_darwin_armx.go.
+// Generates root_darwin_arm64.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
@@ -33,7 +33,7 @@ import (
 	"strings"
 )
 
-var output = flag.String("output", "root_darwin_armx.go", "file name to write")
+var output = flag.String("output", "root_darwin_arm64.go", "file name to write")
 
 func main() {
 	certs, err := selectCerts()
@@ -173,8 +173,6 @@ const header = `
 // license that can be found in the LICENSE file.
 
 // +build cgo
-// +build darwin
-// +build arm arm64 ios
 
 package x509
 

src/crypto/x509/root_darwin_arm_gen.go

@@ -3,10 +3,8 @@
 // license that can be found in the LICENSE file.
 
 // +build lldb
-// +build darwin
-// +build arm arm64
 
-// Used by gcc_signal_darwin_armx.c when doing the test build during cgo.
+// Used by gcc_signal_darwin_arm64.c when doing the test build during cgo.
 // We hope that for real binaries the definition provided by Go will take precedence
 // and the linker will drop this .o file altogether, which is why this definition
 // is all by itself in its own file.

src/runtime/cgo/gcc_darwin_arm.c

@@ -18,8 +18,6 @@
 // The dist tool enables this by build flag when testing.
 
 // +build lldb
-// +build darwin
-// +build arm arm64
 
 #include <limits.h>
 #include <pthread.h>

src/runtime/cgo/gcc_signal2_darwin_armx.c renamed to src/runtime/cgo/gcc_signal2_darwin_arm64.c

@@ -4,7 +4,7 @@
 
 // +build !lldb
 // +build darwin
-// +build arm arm64
+// +build arm64
 
 #include <stdint.h>
 

src/runtime/cgo/gcc_signal_darwin_armx.c renamed to src/runtime/cgo/gcc_signal_darwin_arm64.c

@@ -2,9 +2,6 @@
 // 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 cgo
 
 import _ "unsafe"