Update prebuilts to go1.11 ab/4979655

Test: m -j blueprint_tools
Change-Id: I3c22814607204e2bd3ab0de6e67775f1c052714c
diff --git a/src/syscall/forkpipe2.go b/src/syscall/forkpipe2.go
new file mode 100644
index 0000000..c9a0c49
--- /dev/null
+++ b/src/syscall/forkpipe2.go
@@ -0,0 +1,11 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build freebsd netbsd openbsd
+
+package syscall
+
+func forkExecPipe(p []int) error {
+	return Pipe2(p, O_CLOEXEC)
+}