Start of new ANTLR4 based parser.

Very simple tests pass.

pglablib/sqlast/TypeSpecification.h

@@ -0,0 +1,23 @@
+#pragma once
+
+#include "Node.h"
+#include <QString>
+
+namespace sqlast {
+
+/// These object define not only the base type, but also
+/// parameters used with the type
+/// Think the precision of numeric, max length of char, array
+class TypeSpecification : public Node
+{
+public:
+    TypeSpecification();
+
+private:
+    /// We do not use the PgType from the catalog here as the type used might be defined
+    /// inside the script and not present yet in the catalog.
+    QString baseType;
+    // is_array
+};
+
+}