update github.com/matttproud/golang_protobuf_extensions to 1.0.1

This updates github.com/matttproud/golang_protobuf_extensions to a released
version.
There's no significant change in the code itself, and the corresponding
tests (which are not vendored) behave better with vgo (see details in #65683).

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/.gitignore

@@ -0,0 +1 @@
+cover.dat

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/Makefile

@@ -0,0 +1,7 @@
+all:
+
+cover:
+	go test -cover -v -coverprofile=cover.dat ./...
+	go tool cover -func cover.dat
+
+.PHONY: cover

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/decode.go

@@ -38,7 +38,7 @@ var errInvalidVarint = errors.New("invalid varint32 encountered")
 func ReadDelimited(r io.Reader, m proto.Message) (n int, err error) {
 	// Per AbstractParser#parsePartialDelimitedFrom with
 	// CodedInputStream#readRawVarint32.
-	headerBuf := make([]byte, binary.MaxVarintLen32)
+	var headerBuf [binary.MaxVarintLen32]byte
 	var bytesRead, varIntBytes int
 	var messageLength uint64
 	for varIntBytes == 0 { // i.e. no varint has been decoded yet.

vendor/github.com/matttproud/golang_protobuf_extensions/pbutil/encode.go

@@ -33,8 +33,8 @@ func WriteDelimited(w io.Writer, m proto.Message) (n int, err error) {
 		return 0, err
 	}
 
-	buf := make([]byte, binary.MaxVarintLen32)
-	encodedLength := binary.PutUvarint(buf, uint64(len(buffer)))
+	var buf [binary.MaxVarintLen32]byte
+	encodedLength := binary.PutUvarint(buf[:], uint64(len(buffer)))
 
 	sync, err := w.Write(buf[:encodedLength])
 	if err != nil {