Start of new ANTLR4 based parser.

Very simple tests pass.

pglablib/sqlast/StatementList.cpp

@@ -0,0 +1,24 @@
+#include "StatementList.h"
+#include "Statement.h"
+
+
+using namespace sqlast;
+
+StatementList::StatementList()
+{}
+
+void StatementList::Add(std::unique_ptr<Statement> &&statement)
+{
+    statements.push_back(std::move(statement));
+}
+
+Statement &StatementList::Get(int index)
+{
+    return *statements[index];
+}
+
+int StatementList::Count() const
+{
+    return static_cast<int>(statements.size());
+}
+