encoding/protowire: make package publicly available

Change-Id: I95e293c208e787a91d50e29817620535dfeaa7f2
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/219838
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/testing/prototest/prototest.go b/testing/prototest/prototest.go
index 4fccb70..55a61ae 100644
--- a/testing/prototest/prototest.go
+++ b/testing/prototest/prototest.go
@@ -14,7 +14,7 @@
 	"testing"
 
 	"google.golang.org/protobuf/encoding/prototext"
-	"google.golang.org/protobuf/internal/encoding/wire"
+	"google.golang.org/protobuf/encoding/protowire"
 	"google.golang.org/protobuf/proto"
 	pref "google.golang.org/protobuf/reflect/protoreflect"
 	"google.golang.org/protobuf/reflect/protoregistry"
@@ -488,8 +488,8 @@
 // testUnknown tests the behavior of unknown fields.
 func testUnknown(t testing.TB, m pref.Message) {
 	var b []byte
-	b = wire.AppendTag(b, 1000, wire.VarintType)
-	b = wire.AppendVarint(b, 1001)
+	b = protowire.AppendTag(b, 1000, protowire.VarintType)
+	b = protowire.AppendVarint(b, 1001)
 	m.SetUnknown(pref.RawFields(b))
 	if got, want := []byte(m.GetUnknown()), b; !bytes.Equal(got, want) {
 		t.Errorf("after setting unknown fields:\nGetUnknown() = %v, want %v", got, want)