crypto, pow, vendor: hash optimizations, mmap ethash

vendor/github.com/edsrzf/mmap-go/msync_unix.go

@@ -0,0 +1,14 @@
+// Copyright 2011 Evan Shaw. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux openbsd solaris
+
+package mmap
+
+import (
+	"syscall"
+)
+
+const _SYS_MSYNC = syscall.SYS_MSYNC
+const _MS_SYNC = syscall.MS_SYNC