Add a constructor to PSymbolTable that takes a parent table as input

src/dobjtype.cpp

@@ -2507,6 +2507,11 @@ PSymbolTable::PSymbolTable()
 {
 }
 
+PSymbolTable::PSymbolTable(PSymbolTable *parent)
+: ParentSymbolTable(parent)
+{
+}
+
 PSymbolTable::~PSymbolTable ()
 {
 	ReleaseSymbols();

src/dobjtype.h

@@ -73,6 +73,7 @@ public:
 struct PSymbolTable
 {
 	PSymbolTable();
+	PSymbolTable(PSymbolTable *parent);
 	~PSymbolTable();
 
 	size_t MarkSymbols();

src/zscript/zcc_parser.cpp

@@ -255,7 +255,7 @@ static void DoParse(const char *filename)
 	ZCCParse(parser, 0, value, &state);
 	ZCCParseFree(parser, free);
 
-	PSymbolTable symbols;
+	PSymbolTable symbols(&GlobalSymbols);
 	ZCCCompiler cc(state, NULL, symbols);
 	cc.Compile();
 #ifdef _DEBUG