Fix OSX build error in outdated golang.org/x/sys dependency

[devnev]

Updated to the version mentioned in:

https://go-review.googlesource.com/c/debug/+/359596/

Referenced from:

golang/go#49219

Example of errors:

$ go build ./...
# golang.org/x/sys/unix
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/syscall_darwin.1_13.go:29:3: //go:linkname must refer to declared function or variable
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/zsyscall_darwin_amd64.1_13.go:27:3: //go:linkname must refer to declared function or variable
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/zsyscall_darwin_amd64.1_13.go:40:3: //go:linkname must refer to declared function or variable
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/zsyscall_darwin_amd64.go:28:3: //go:linkname must refer to declared function or variable
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/zsyscall_darwin_amd64.go:43:3: //go:linkname must refer to declared function or variable
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/zsyscall_darwin_amd64.go:59:3: //go:linkname must refer to declared function or variable
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/zsyscall_darwin_amd64.go:75:3: //go:linkname must refer to declared function or variable
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/zsyscall_darwin_amd64.go:90:3: //go:linkname must refer to declared function or variable
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/zsyscall_darwin_amd64.go:105:3: //go:linkname must refer to declared function or variable
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/zsyscall_darwin_amd64.go:121:3: //go:linkname must refer to declared function or variable
../../.local/go/pkg/mod/golang.org/x/sys@v0.0.0-20200930185726-fdedc70b468f/unix/zsyscall_darwin_amd64.go:121:3: too many errors

This is just to fix the build, a general update of the go version and all the golang.org/x/... dependencies is needed.

[johanbrandhorst]

Thanks for your contribution!