vendor protobuf & grpc

Signed-off-by: Akihiro Suda <akihiro.suda.cz@hco.ntt.co.jp>

vendor/github.com/gogo/protobuf/plugin/size/size.go

@@ -141,6 +141,7 @@ type size struct {
 	atleastOne bool
 	localName  string
 	typesPkg   generator.Single
+	bitsPkg    generator.Single
 }
 
 func NewSize() *size {
@@ -188,14 +189,7 @@ func keySize(fieldNumber int32, wireType int) int {
 func (p *size) sizeVarint() {
 	p.P(`
 	func sov`, p.localName, `(x uint64) (n int) {
-		for {
-			n++
-			x >>= 7
-			if x == 0 {
-				break
-			}
-		}
-		return n
+                return (`, p.bitsPkg.Use(), `.Len64(x | 1) + 6)/ 7
 	}`)
 }
 
@@ -589,6 +583,7 @@ func (p *size) Generate(file *generator.FileDescriptor) {
 	p.localName = generator.FileName(file)
 	p.typesPkg = p.NewImport("github.com/gogo/protobuf/types")
 	protoPkg := p.NewImport("github.com/gogo/protobuf/proto")
+	p.bitsPkg = p.NewImport("math/bits")
 	if !gogoproto.ImportsGoGoProto(file.FileDescriptorProto) {
 		protoPkg = p.NewImport("github.com/golang/protobuf/proto")
 	}