Revert "windows: make zsyscall_windows.go generatable on non-WSL env"

This reverts commit ad28b68e88.

Reason for revert: It completely breaks 'go generate' on windows

Update golang/go#32349

Change-Id: I4bedc6cf5130eb48c18c3208c8029433407430e4
Reviewed-on: https://go-review.googlesource.com/c/sys/+/179580
Reviewed-by: Takuto Ikuta <tikuta@google.com>
Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com>

windows/generate.bash

@@ -1,15 +0,0 @@
-#!/bin/bash
-
-# Copyright 2019 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.
-
-set -e
-
-# For successful zsyscall_windows.go generation on non-WSL env, this should
-# run before mkerrors.bash.
-echo "# Generating zsyscall_windows.go ..."
-go run $(go env GOROOT)/src/syscall/mksyscall_windows.go -output zsyscall_windows.go eventlog.go service.go syscall_windows.go security_windows.go
-
-echo "# Generating zerrors_windows.go ..."
-./mkerrors.bash zerrors_windows.go

windows/mkerrors.bash

@@ -9,7 +9,7 @@ shopt -s nullglob
 
 [[ $# -eq 1 ]] || { echo "Usage: $0 OUTPUT_FILE.go" >&2; exit 1; }
 winerror="$(printf '%s\n' "/mnt/c/Program Files (x86)/Windows Kits/"/*/Include/*/shared/winerror.h | sort -Vr | head -n 1)"
-[[ -n $winerror ]] || { echo "Unable to find winerror.h; this expects to be run on Windows with WSL" >&2; exit 1; }
+[[ -n $winerror ]] || { echo "Unable to find winerror.h" >&2; exit 1; }
 
 declare -A errors
 

windows/mkerrors.go

@@ -6,4 +6,4 @@
 
 package windows
 
-//go:generate ./generate.bash
+//go:generate ./mkerrors.bash zerrors_windows.go

windows/mksyscall.go

@@ -0,0 +1,9 @@
+// Copyright 2009 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 generate
+
+package windows
+
+//go:generate go run $GOROOT/src/syscall/mksyscall_windows.go -output zsyscall_windows.go eventlog.go service.go syscall_windows.go security_windows.go