diff --git a/vendor/google.golang.org/protobuf/internal/set/ints.go b/vendor/google.golang.org/protobuf/internal/set/ints.go
new file mode 100644
index 0000000..d3d7f89
--- /dev/null
+++ b/vendor/google.golang.org/protobuf/internal/set/ints.go
@@ -0,0 +1,58 @@
+// Copyright 2018 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.
+
+// Package set provides simple set data structures for uint64s.
+package set
+
+import "math/bits"
+
+// int64s represents a set of integers within the range of 0..63.
+type int64s uint64
+
+func (bs *int64s) Len() int {
+	return bits.OnesCount64(uint64(*bs))
+}
+func (bs *int64s) Has(n uint64) bool {
+	return uint64(*bs)&(uint64(1)<<n) > 0
+}
+func (bs *int64s) Set(n uint64) {
+	*(*uint64)(bs) |= uint64(1) << n
+}
+func (bs *int64s) Clear(n uint64) {
+	*(*uint64)(bs) &^= uint64(1) << n
+}
+
+// Ints represents a set of integers within the range of 0..math.MaxUint64.
+type Ints struct {
+	lo int64s
+	hi map[uint64]struct{}
+}
+
+func (bs *Ints) Len() int {
+	return bs.lo.Len() + len(bs.hi)
+}
+func (bs *Ints) Has(n uint64) bool {
+	if n < 64 {
+		return bs.lo.Has(n)
+	}
+	_, ok := bs.hi[n]
+	return ok
+}
+func (bs *Ints) Set(n uint64) {
+	if n < 64 {
+		bs.lo.Set(n)
+		return
+	}
+	if bs.hi == nil {
+		bs.hi = make(map[uint64]struct{})
+	}
+	bs.hi[n] = struct{}{}
+}
+func (bs *Ints) Clear(n uint64) {
+	if n < 64 {
+		bs.lo.Clear(n)
+		return
+	}
+	delete(bs.hi, n)
+}