runtime, syscall: add a couple of hurd build tags

Patch by Svante Signell.

Updates https://gcc.gnu.org/PR93468

Change-Id: Ibb31bee789aaed48875698fa6286d0d8c255f36f
Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/216959
Reviewed-by: Ian Lance Taylor <iant@golang.org>
diff --git a/libgo/go/runtime/nbpipe_pipe2.go b/libgo/go/runtime/nbpipe_pipe2.go
index e3639d9..76fb40c 100644
--- a/libgo/go/runtime/nbpipe_pipe2.go
+++ b/libgo/go/runtime/nbpipe_pipe2.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build freebsd linux netbsd openbsd solaris
+// +build freebsd hurd linux netbsd openbsd solaris
 
 package runtime
 
diff --git a/libgo/go/syscall/sockcmsg_unix_other.go b/libgo/go/syscall/sockcmsg_unix_other.go
index 65d9f18..3e7afe4 100644
--- a/libgo/go/syscall/sockcmsg_unix_other.go
+++ b/libgo/go/syscall/sockcmsg_unix_other.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build aix darwin freebsd linux netbsd openbsd solaris
+// +build aix darwin freebsd hurd linux netbsd openbsd solaris
 
 package syscall