all: Become a Go module (fixes #5148) (#5384)

* go mod init; rm -rf vendor

* tweak proto files and generation

* go mod vendor

* clean up build.go

* protobuf literals in tests

* downgrade gogo/protobuf

vendor/golang.org/x/sys/unix/sockcmsg_unix.go

@@ -2,23 +2,36 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build darwin dragonfly freebsd linux netbsd openbsd solaris
+// +build aix darwin dragonfly freebsd linux netbsd openbsd solaris
 
 // Socket control messages
 
 package unix
 
-import "unsafe"
+import (
+	"runtime"
+	"unsafe"
+)
 
 // Round the length of a raw sockaddr up to align it properly.
 func cmsgAlignOf(salen int) int {
-	salign := sizeofPtr
-	// NOTE: It seems like 64-bit Darwin, DragonFly BSD and
-	// Solaris kernels still require 32-bit aligned access to
-	// network subsystem.
-	if darwin64Bit || dragonfly64Bit || solaris64Bit {
-		salign = 4
+	salign := SizeofPtr
+
+	switch runtime.GOOS {
+	case "darwin", "dragonfly", "solaris":
+		// NOTE: It seems like 64-bit Darwin, DragonFly BSD and
+		// Solaris kernels still require 32-bit aligned access to
+		// network subsystem.
+		if SizeofPtr == 8 {
+			salign = 4
+		}
+	case "openbsd":
+		// OpenBSD armv7 requires 64-bit alignment.
+		if runtime.GOARCH == "arm" {
+			salign = 8
+		}
 	}
+
 	return (salen + salign - 1) & ^(salign - 1)
 }