unit tests

Signed-off-by: Casey Lee <cplee@nektos.com>

vendor/golang.org/x/sys/cpu/cpu_riscv64.go

@@ -0,0 +1,9 @@
+// Copyright 2019 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 riscv64
+
+package cpu
+
+const cacheLineSize = 32