- create struct types.

- fixed class creation. There was an infinite loop and some missing checks for native classes.
- do not write the compiler's symbols to the same symbol table as the output. The output must go to GlobalSymbols but the internal symbols must go to a namespace specific table that can be discarded after compilation.

src/zscript/zcc_parser.cpp

@@ -338,7 +338,8 @@ static void DoParse(int lumpnum)
 #endif
 	}
 
-	ZCCCompiler cc(state, NULL, GlobalSymbols);
+	PSymbolTable symtable(&GlobalSymbols);
+	ZCCCompiler cc(state, NULL, symtable, GlobalSymbols);
 	cc.Compile();
 	// ... and another one afterward so we can see what the compiler does with the data.
 #ifdef _DEBUG