Don't omit opaque types for real empty structs in DXIL editing

renderdoc/driver/shaders/dxil/dxil_bytecode.cpp

@@ -754,6 +754,7 @@ Program::Program(const byte *bytes, size_t length)
           {
             // pretend opaque types are empty structs
             m_Types[typeIndex].type = Type::Struct;
+            m_Types[typeIndex].opaque = true;
 
             typeIndex++;
           }

renderdoc/driver/shaders/dxil/dxil_bytecode.h

@@ -103,7 +103,7 @@ struct Type
   const Type *inner = NULL;
 
   // struct or function
-  bool packedStruct = false, vararg = false;
+  bool packedStruct = false, vararg = false, opaque = false;
   uint16_t id = 0xFFFF;
   rdcstr name;
   rdcarray<const Type *> members;    // the members for a struct, the parameters for functions

renderdoc/driver/shaders/dxil/dxil_bytecode_editor.cpp

@@ -1020,7 +1020,7 @@ bytebuf ProgramEditor::EncodeProgram() const
       }
       else if(m_Types[i].type == Type::Struct)
       {
-        if(m_Types[i].members.empty())
+        if(m_Types[i].opaque)
         {
           writer.Record(LLVMBC::TypeRecord::OPAQUE);
         }