fix test harness for previous commit (fix loading emptypb)

Related to https://github.com/golang/open2opaque/issues/18

PiperOrigin-RevId: 799446811
Change-Id: I14dee49f9f615697236e8cc8d8aa2888d546dbfd

internal/fix/fiximports.go

diff --git a/internal/fix/fiximports.go b/internal/fix/fiximports.go
index 9131c32..63a3096 100644
--- a/internal/fix/fiximports.go
+++ b/internal/fix/fiximports.go
@@ -138,7 +138,12 @@
 // name and replace it with something more descriptive and more inline with the
 // respective team style.
 func (imp *imports) findAvailableName(path string) string {
-	if !strings.HasSuffix(path, "go_proto") {
+	// Google-internally, all protobuf generated code packages end in go_proto.
+	// Externally, we at least recognize the well-known types,
+	// such that our tests behave the same way internally and externally.
+	isProtoImport := strings.HasSuffix(path, "go_proto") ||
+		strings.HasPrefix(path, "google.golang.org/protobuf/types/")
+	if !isProtoImport {
 		// default name for non proto imports, assumed to be available
 		return filepath.Base(path)
 	}

internal/fix/rules_commonload_test.go

diff --git a/internal/fix/rules_commonload_test.go b/internal/fix/rules_commonload_test.go
index 86e4177..2965836 100644
--- a/internal/fix/rules_commonload_test.go
+++ b/internal/fix/rules_commonload_test.go
@@ -47,6 +47,7 @@
 		"google.golang.org/open2opaque/internal/fix/testdata/proto3test_go_proto": true,
 		"google.golang.org/protobuf/proto":                                        true,
 		"google.golang.org/protobuf/types/gofeaturespb":                           true,
+		"google.golang.org/protobuf/types/known/emptypb":                          true,
 		// Imported by .pb.go files:
 		"google.golang.org/protobuf/reflect/protoreflect": true,
 		"google.golang.org/protobuf/runtime/protoimpl":    true,