s390x doesn't have sendfile64 so apply the same fix as MIPS
(
eebf7d27) and just use sendfile.
Change-Id: If8fe2e974ed44a9883282430157c3545d5bd04bd
Reviewed-on: https://go-review.googlesource.com/21892
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
 
 
        syscalls := "sendfile,sendfile64"
        switch runtime.GOARCH {
-       case "mips64", "mips64le":
-               // mips64 strace doesn't support sendfile64 and will error out
-               // if we specify that with `-e trace='.
+       case "mips64", "mips64le", "s390x":
+               // strace on the above platforms doesn't support sendfile64
+               // and will error out if we specify that with `-e trace='.
                syscalls = "sendfile"
        }