unix: remove recently introduced debug/elf dependency CL 501795 added a dependency on debug/elf (and thus compress/gzip, debug/dwarf, hash/adler32) Add a copy of the const instead. Change-Id: I2c86094ef7de61b8dd0bdd727f6e547ac7f58527 Reviewed-on: https://go-review.googlesource.com/c/sys/+/502356 Reviewed-by: Tobias Klauser <tobias.klauser@gmail.com> Reviewed-by: David Chase <drchase@google.com> Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org> Reviewed-by: Ian Lance Taylor <iant@google.com> Auto-Submit: Brad Fitzpatrick <bradfitz@golang.org> TryBot-Result: Gopher Robot <gobot@golang.org>

diff --git a/unix/syscall_linux.go b/unix/syscall_linux.go
index ec24fae..6de486b 100644
--- a/unix/syscall_linux.go
+++ b/unix/syscall_linux.go

@@ -12,7 +12,6 @@
 package unix
 
 import (
-	"debug/elf"
 	"encoding/binary"
 	"strconv"
 	"syscall"
@@ -1700,18 +1699,23 @@
 	return ptracePoke(PTRACE_POKEUSR, PTRACE_PEEKUSR, pid, addr, data)
 }
 
+// elfNT_PRSTATUS is a copy of the debug/elf.NT_PRSTATUS constant so
+// x/sys/unix doesn't need to depend on debug/elf and thus
+// compress/zlib, debug/dwarf, and other packages.
+const elfNT_PRSTATUS = 1
+
 func PtraceGetRegs(pid int, regsout *PtraceRegs) (err error) {
 	var iov Iovec
 	iov.Base = (*byte)(unsafe.Pointer(regsout))
 	iov.SetLen(int(unsafe.Sizeof(*regsout)))
-	return ptracePtr(PTRACE_GETREGSET, pid, uintptr(elf.NT_PRSTATUS), unsafe.Pointer(&iov))
+	return ptracePtr(PTRACE_GETREGSET, pid, uintptr(elfNT_PRSTATUS), unsafe.Pointer(&iov))
 }
 
 func PtraceSetRegs(pid int, regs *PtraceRegs) (err error) {
 	var iov Iovec
 	iov.Base = (*byte)(unsafe.Pointer(regs))
 	iov.SetLen(int(unsafe.Sizeof(*regs)))
-	return ptracePtr(PTRACE_SETREGSET, pid, uintptr(elf.NT_PRSTATUS), unsafe.Pointer(&iov))
+	return ptracePtr(PTRACE_SETREGSET, pid, uintptr(elfNT_PRSTATUS), unsafe.Pointer(&iov))
 }
 
 func PtraceSetOptions(pid int, options int) (err error) {