Pull request: all: imp build tags

Updates #2419.

Squashed commit of the following:

commit e57e6ce56c59d4ef42b1716247fe48a86404179e
Author: Ainar Garipov <A.Garipov@AdGuard.COM>
Date:   Tue Jun 15 19:37:15 2021 +0300

    all: imp build tags

internal/aghos/endian_big.go

@@ -1,6 +1,5 @@
-// +build mips mips64
-
 //go:build mips || mips64
+// +build mips mips64
 
 // This file is an adapted version of github.com/josharian/native.
 

internal/aghos/endian_little.go

@@ -1,6 +1,5 @@
-// +build amd64 386 arm arm64 mipsle mips64le ppc64le
-
 //go:build amd64 || 386 || arm || arm64 || mipsle || mips64le || ppc64le
+// +build amd64 386 arm arm64 mipsle mips64le ppc64le
 
 // This file is an adapted version of github.com/josharian/native.
 

internal/aghos/os_bsd.go

@@ -1,6 +1,5 @@
-// +build darwin netbsd openbsd
-
 //go:build darwin || netbsd || openbsd
+// +build darwin netbsd openbsd
 
 package aghos
 

internal/aghos/os_freebsd.go

@@ -1,6 +1,5 @@
-// +build freebsd
-
 //go:build freebsd
+// +build freebsd
 
 package aghos
 

internal/aghos/os_linux.go

@@ -1,6 +1,5 @@
-// +build linux
-
 //go:build linux
+// +build linux
 
 package aghos
 

internal/aghos/os_windows.go

@@ -1,6 +1,5 @@
-// +build windows
-
 //go:build windows
+// +build windows
 
 package aghos
 

internal/aghos/syslog_others.go

@@ -1,6 +1,5 @@
-// +build !windows,!plan9
-
 //go:build !(windows || plan9)
+// +build !windows,!plan9
 
 package aghos
 

internal/aghos/syslog_windows.go

@@ -1,6 +1,5 @@
-// +build windows plan9
-
 //go:build windows || plan9
+// +build windows plan9
 
 package aghos
 

internal/aghos/user_unix.go

@@ -1,6 +1,5 @@
-// +build darwin freebsd linux netbsd openbsd
-
 //go:build darwin || freebsd || linux || netbsd || openbsd
+// +build darwin freebsd linux netbsd openbsd
 
 package aghos
 

internal/aghos/user_windows.go

@@ -1,6 +1,5 @@
-// +build windows
-
 //go:build windows
+// +build windows
 
 package aghos