undo CL 107150043 / caa2646daa63

preparing for the syscall package freeze.
the change for issue 8218 is only applied to go.sys/unix.

««« original CL description
syscall: implement setresuid(2) and setresgid(2) on OpenBSD/FreeBSD/DragonflyBSD

Fixes #8218.

LGTM=iant
R=golang-codereviews, iant, minux
CC=golang-codereviews
https://golang.org/cl/107150043

»»»

LGTM=r
R=r, iant, golang-codereviews
CC=golang-codereviews
https://golang.org/cl/138840044
diff --git a/src/pkg/syscall/syscall_dragonfly.go b/src/pkg/syscall/syscall_dragonfly.go
index b17e77d..39c51df 100644
--- a/src/pkg/syscall/syscall_dragonfly.go
+++ b/src/pkg/syscall/syscall_dragonfly.go
@@ -183,8 +183,6 @@
 //sys	Setpriority(which int, who int, prio int) (err error)
 //sysnb	Setregid(rgid int, egid int) (err error)
 //sysnb	Setreuid(ruid int, euid int) (err error)
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error)
 //sysnb	Setrlimit(which int, lim *Rlimit) (err error)
 //sysnb	Setsid() (pid int, err error)
 //sysnb	Settimeofday(tp *Timeval) (err error)
diff --git a/src/pkg/syscall/syscall_freebsd.go b/src/pkg/syscall/syscall_freebsd.go
index 959d46b..3d834f5 100644
--- a/src/pkg/syscall/syscall_freebsd.go
+++ b/src/pkg/syscall/syscall_freebsd.go
@@ -205,8 +205,6 @@
 //sys	Setpriority(which int, who int, prio int) (err error)
 //sysnb	Setregid(rgid int, egid int) (err error)
 //sysnb	Setreuid(ruid int, euid int) (err error)
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error)
 //sysnb	Setrlimit(which int, lim *Rlimit) (err error)
 //sysnb	Setsid() (pid int, err error)
 //sysnb	Settimeofday(tp *Timeval) (err error)
diff --git a/src/pkg/syscall/syscall_openbsd.go b/src/pkg/syscall/syscall_openbsd.go
index a46f6ae..8d3f825 100644
--- a/src/pkg/syscall/syscall_openbsd.go
+++ b/src/pkg/syscall/syscall_openbsd.go
@@ -182,8 +182,6 @@
 //sys	Setpriority(which int, who int, prio int) (err error)
 //sysnb	Setregid(rgid int, egid int) (err error)
 //sysnb	Setreuid(ruid int, euid int) (err error)
-//sysnb	Setresgid(rgid int, egid int, sgid int) (err error)
-//sysnb	Setresuid(ruid int, euid int, suid int) (err error)
 //sysnb	Setrlimit(which int, lim *Rlimit) (err error)
 //sysnb	Setsid() (pid int, err error)
 //sysnb	Settimeofday(tp *Timeval) (err error)
@@ -274,6 +272,8 @@
 // semop
 // setgroups
 // setitimer
+// setresgid
+// setresuid
 // setrtable
 // setsockopt
 // shmat
diff --git a/src/pkg/syscall/zsyscall_dragonfly_386.go b/src/pkg/syscall/zsyscall_dragonfly_386.go
index 94a716f..0ec8132 100644
--- a/src/pkg/syscall/zsyscall_dragonfly_386.go
+++ b/src/pkg/syscall/zsyscall_dragonfly_386.go
@@ -1059,26 +1059,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(which int, lim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
diff --git a/src/pkg/syscall/zsyscall_dragonfly_amd64.go b/src/pkg/syscall/zsyscall_dragonfly_amd64.go
index 89c22ed..8c7cce5 100644
--- a/src/pkg/syscall/zsyscall_dragonfly_amd64.go
+++ b/src/pkg/syscall/zsyscall_dragonfly_amd64.go
@@ -1059,26 +1059,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(which int, lim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
diff --git a/src/pkg/syscall/zsyscall_freebsd_386.go b/src/pkg/syscall/zsyscall_freebsd_386.go
index 61e4888..5befe83 100644
--- a/src/pkg/syscall/zsyscall_freebsd_386.go
+++ b/src/pkg/syscall/zsyscall_freebsd_386.go
@@ -1059,26 +1059,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(which int, lim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
diff --git a/src/pkg/syscall/zsyscall_freebsd_amd64.go b/src/pkg/syscall/zsyscall_freebsd_amd64.go
index 5e3afe1..ab2eb80 100644
--- a/src/pkg/syscall/zsyscall_freebsd_amd64.go
+++ b/src/pkg/syscall/zsyscall_freebsd_amd64.go
@@ -1059,26 +1059,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(which int, lim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
diff --git a/src/pkg/syscall/zsyscall_freebsd_arm.go b/src/pkg/syscall/zsyscall_freebsd_arm.go
index da1f2d5..c1f0f90 100644
--- a/src/pkg/syscall/zsyscall_freebsd_arm.go
+++ b/src/pkg/syscall/zsyscall_freebsd_arm.go
@@ -1059,26 +1059,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(which int, lim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
diff --git a/src/pkg/syscall/zsyscall_openbsd_386.go b/src/pkg/syscall/zsyscall_openbsd_386.go
index 068a1fb..785e7c3 100644
--- a/src/pkg/syscall/zsyscall_openbsd_386.go
+++ b/src/pkg/syscall/zsyscall_openbsd_386.go
@@ -1049,26 +1049,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(which int, lim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {
diff --git a/src/pkg/syscall/zsyscall_openbsd_amd64.go b/src/pkg/syscall/zsyscall_openbsd_amd64.go
index 13dc093..7a8d9b6 100644
--- a/src/pkg/syscall/zsyscall_openbsd_amd64.go
+++ b/src/pkg/syscall/zsyscall_openbsd_amd64.go
@@ -1049,26 +1049,6 @@
 
 // THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
 
-func Setresgid(rgid int, egid int, sgid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESGID, uintptr(rgid), uintptr(egid), uintptr(sgid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
-func Setresuid(ruid int, euid int, suid int) (err error) {
-	_, _, e1 := RawSyscall(SYS_SETRESUID, uintptr(ruid), uintptr(euid), uintptr(suid))
-	if e1 != 0 {
-		err = e1
-	}
-	return
-}
-
-// THIS FILE IS GENERATED BY THE COMMAND AT THE TOP; DO NOT EDIT
-
 func Setrlimit(which int, lim *Rlimit) (err error) {
 	_, _, e1 := RawSyscall(SYS_SETRLIMIT, uintptr(which), uintptr(unsafe.Pointer(lim)), 0)
 	if e1 != 0 {