windows: gofmt to add go:build lines

Change-Id: I71b9023fcb6c9860ea35ba0d2cf77a6eed5176b9
Reviewed-on: https://go-review.googlesource.com/c/sys/+/357329
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: David Crawshaw <crawshaw@golang.org>
Trust: Jason A. Donenfeld <Jason@zx2c4.com>
Trust: David Crawshaw <crawshaw@golang.org>
Run-TryBot: Jason A. Donenfeld <Jason@zx2c4.com>
TryBot-Result: Go Bot <gobot@golang.org>
diff --git a/windows/aliases.go b/windows/aliases.go
index af3af60..a20ebea 100644
--- a/windows/aliases.go
+++ b/windows/aliases.go
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build windows
-// +build go1.9
+//go:build windows && go1.9
+// +build windows,go1.9
 
 package windows
 
diff --git a/windows/eventlog.go b/windows/eventlog.go
index 40af946..2cd6064 100644
--- a/windows/eventlog.go
+++ b/windows/eventlog.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 package windows
diff --git a/windows/mksyscall.go b/windows/mksyscall.go
index 328e3b2..6102910 100644
--- a/windows/mksyscall.go
+++ b/windows/mksyscall.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build generate
 // +build generate
 
 package windows
diff --git a/windows/race.go b/windows/race.go
index a74e3e2..9196b08 100644
--- a/windows/race.go
+++ b/windows/race.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows && race
 // +build windows,race
 
 package windows
diff --git a/windows/race0.go b/windows/race0.go
index e44a3cb..7bae481 100644
--- a/windows/race0.go
+++ b/windows/race0.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows && !race
 // +build windows,!race
 
 package windows
diff --git a/windows/service.go b/windows/service.go
index 1a22b3e..5b28ae1 100644
--- a/windows/service.go
+++ b/windows/service.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 package windows
diff --git a/windows/str.go b/windows/str.go
index 917cc2a..4fc0143 100644
--- a/windows/str.go
+++ b/windows/str.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 package windows
diff --git a/windows/syscall.go b/windows/syscall.go
index 6122f55..72074d5 100644
--- a/windows/syscall.go
+++ b/windows/syscall.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 // Package windows contains an interface to the low-level operating system
diff --git a/windows/syscall_test.go b/windows/syscall_test.go
index af3ff32..fd4a015 100644
--- a/windows/syscall_test.go
+++ b/windows/syscall_test.go
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+//go:build windows
 // +build windows
 
 package windows_test