[Upb C++] Generate class scoped declarations for enumerations.

PiperOrigin-RevId: 512191989
diff --git a/protos_generator/gen_enums.h b/protos_generator/gen_enums.h
index 8e7d6ea..00c7ca4 100644
--- a/protos_generator/gen_enums.h
+++ b/protos_generator/gen_enums.h
@@ -34,6 +34,9 @@
 namespace protobuf = ::google::protobuf;
 
 std::string EnumTypeName(const protobuf::EnumDescriptor* enum_descriptor);
+std::string EnumValueSymbolInNameSpace(
+    const protobuf::EnumDescriptor* desc,
+    const protobuf::EnumValueDescriptor* value);
 void WriteHeaderEnumForwardDecls(
     std::vector<const protobuf::EnumDescriptor*>& enums, Output& output);
 void WriteEnumDeclarations(