Switch to using the dep tool and update all the dependencies

vendor/golang.org/x/crypto/blake2s/blake2s_amd64.go

@@ -0,0 +1,39 @@
+// Copyright 2016 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 amd64,!gccgo,!appengine
+
+package blake2s
+
+var (
+	useSSE4    = supportSSE4()
+	useSSSE3   = supportSSSE3()
+	useSSE2    = true // Always available on amd64
+	useGeneric = false
+)
+
+//go:noescape
+func supportSSSE3() bool
+
+//go:noescape
+func supportSSE4() bool
+
+//go:noescape
+func hashBlocksSSE2(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte)
+
+//go:noescape
+func hashBlocksSSSE3(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte)
+
+//go:noescape
+func hashBlocksSSE4(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte)
+
+func hashBlocks(h *[8]uint32, c *[2]uint32, flag uint32, blocks []byte) {
+	if useSSE4 {
+		hashBlocksSSE4(h, c, flag, blocks)
+	} else if useSSSE3 {
+		hashBlocksSSSE3(h, c, flag, blocks)
+	} else {
+		hashBlocksSSE2(h, c, flag, blocks)
+	}
+}