Revert "unix: add Pipe2 on netbsd"

This reverts CL 283593.

Reason for revert: breaks DragonflyBSD builders and was submitted during code freeze.

Change-Id: I784f58ae56f7259d5176921d7a61070e0ac7cb52
Reviewed-on: https://go-review.googlesource.com/c/sys/+/283597
Trust: Tobias Klauser <tobias.klauser@gmail.com>
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>
diff --git a/unix/pipe2_test.go b/unix/pipe2_test.go
deleted file mode 100644
index 3cd3bbd..0000000
--- a/unix/pipe2_test.go
+++ /dev/null
@@ -1,55 +0,0 @@
-// Copyright 2021 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 dragonfly freebsd linux netbsd openbsd solaris
-
-package unix_test
-
-import (
-	"testing"
-
-	"golang.org/x/sys/unix"
-)
-
-func TestPipe2(t *testing.T) {
-	const s = "hello"
-	var pipes [2]int
-	err := unix.Pipe2(pipes[:], 0)
-	if err != nil {
-		t.Fatalf("pipe2: %v", err)
-	}
-	r := pipes[0]
-	w := pipes[1]
-	go func() {
-		n, err := unix.Write(w, []byte(s))
-		if err != nil {
-			t.Errorf("bad write: %v", err)
-			return
-		}
-		if n != len(s) {
-			t.Errorf("bad write count: %d", n)
-			return
-		}
-		err = unix.Close(w)
-		if err != nil {
-			t.Errorf("bad close: %v", err)
-			return
-		}
-	}()
-	var buf [10 + len(s)]byte
-	n, err := unix.Read(r, buf[:])
-	if err != nil {
-		t.Fatalf("bad read: %v", err)
-	}
-	if n != len(s) {
-		t.Fatalf("bad read count: %d", n)
-	}
-	if string(buf[:n]) != s {
-		t.Fatalf("bad contents: %s", string(buf[:n]))
-	}
-	err = unix.Close(r)
-	if err != nil {
-		t.Fatalf("bad close: %v", err)
-	}
-}
diff --git a/unix/syscall_netbsd.go b/unix/syscall_netbsd.go
index 93a1462..1e6843b 100644
--- a/unix/syscall_netbsd.go
+++ b/unix/syscall_netbsd.go
@@ -111,7 +111,6 @@
 }
 
 //sysnb pipe() (fd1 int, fd2 int, err error)
-
 func Pipe(p []int) (err error) {
 	if len(p) != 2 {
 		return EINVAL
@@ -120,21 +119,7 @@
 	return
 }
 
-//sysnb	pipe2(p *[2]_C_int, flags int) (err error)
-
-func Pipe2(p []int, flags int) error {
-	if len(p) != 2 {
-		return EINVAL
-	}
-	var pp [2]_C_int
-	err := pipe2(&pp, flags)
-	p[0] = int(pp[0])
-	p[1] = int(pp[1])
-	return err
-}
-
 //sys Getdents(fd int, buf []byte) (n int, err error)
-
 func Getdirentries(fd int, buf []byte, basep *uintptr) (n int, err error) {
 	n, err = Getdents(fd, buf)
 	if err != nil || basep == nil {
diff --git a/unix/syscall_solaris_test.go b/unix/syscall_solaris_test.go
index d3e7d2b..ae2c40c 100644
--- a/unix/syscall_solaris_test.go
+++ b/unix/syscall_solaris_test.go
@@ -13,6 +13,48 @@
 	"golang.org/x/sys/unix"
 )
 
+func TestPipe2(t *testing.T) {
+	const s = "hello"
+	var pipes [2]int
+	err := unix.Pipe2(pipes[:], 0)
+	if err != nil {
+		t.Fatalf("pipe2: %v", err)
+	}
+	r := pipes[0]
+	w := pipes[1]
+	go func() {
+		n, err := unix.Write(w, []byte(s))
+		if err != nil {
+			t.Errorf("bad write: %v", err)
+			return
+		}
+		if n != len(s) {
+			t.Errorf("bad write count: %d", n)
+			return
+		}
+		err = unix.Close(w)
+		if err != nil {
+			t.Errorf("bad close: %v", err)
+			return
+		}
+	}()
+	var buf [10 + len(s)]byte
+	n, err := unix.Read(r, buf[:])
+	if err != nil {
+		t.Fatalf("bad read: %v", err)
+	}
+	if n != len(s) {
+		t.Fatalf("bad read count: %d", n)
+	}
+	if string(buf[:n]) != s {
+		t.Fatalf("bad contents: %s", string(buf[:n]))
+	}
+	err = unix.Close(r)
+	if err != nil {
+		t.Fatalf("bad close: %v", err)
+	}
+}
+
 func TestStatvfs(t *testing.T) {
 	if err := unix.Statvfs("", nil); err == nil {
 		t.Fatal(`Statvfs("") expected failure`)
diff --git a/unix/zsyscall_netbsd_386.go b/unix/zsyscall_netbsd_386.go
index 1d6f71d..3bbd9e3 100644
--- a/unix/zsyscall_netbsd_386.go
+++ b/unix/zsyscall_netbsd_386.go
@@ -362,16 +362,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func pipe2(p *[2]_C_int, flags int) (err error) {
-	_, _, e1 := RawSyscall(SYS_PIPE2, uintptr(unsafe.Pointer(p)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getdents(fd int, buf []byte) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(buf) > 0 {
diff --git a/unix/zsyscall_netbsd_amd64.go b/unix/zsyscall_netbsd_amd64.go
index 82f5050..d8cf501 100644
--- a/unix/zsyscall_netbsd_amd64.go
+++ b/unix/zsyscall_netbsd_amd64.go
@@ -362,16 +362,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func pipe2(p *[2]_C_int, flags int) (err error) {
-	_, _, e1 := RawSyscall(SYS_PIPE2, uintptr(unsafe.Pointer(p)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getdents(fd int, buf []byte) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(buf) > 0 {
diff --git a/unix/zsyscall_netbsd_arm.go b/unix/zsyscall_netbsd_arm.go
index b4db55a..1153fe6 100644
--- a/unix/zsyscall_netbsd_arm.go
+++ b/unix/zsyscall_netbsd_arm.go
@@ -362,16 +362,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func pipe2(p *[2]_C_int, flags int) (err error) {
-	_, _, e1 := RawSyscall(SYS_PIPE2, uintptr(unsafe.Pointer(p)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getdents(fd int, buf []byte) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(buf) > 0 {
diff --git a/unix/zsyscall_netbsd_arm64.go b/unix/zsyscall_netbsd_arm64.go
index e9f6d79..24b4ebb 100644
--- a/unix/zsyscall_netbsd_arm64.go
+++ b/unix/zsyscall_netbsd_arm64.go
@@ -362,16 +362,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func pipe2(p *[2]_C_int, flags int) (err error) {
-	_, _, e1 := RawSyscall(SYS_PIPE2, uintptr(unsafe.Pointer(p)), uintptr(flags), 0)
-	if e1 != 0 {
-		err = errnoErr(e1)
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Getdents(fd int, buf []byte) (n int, err error) {
 	var _p0 unsafe.Pointer
 	if len(buf) > 0 {