Re-implement LIMIT/OFFSET as a plan node type, instead of a hack in

ExecutorRun.  This allows LIMIT to work in a view.  Also, LIMIT in a
cursor declaration will behave in a reasonable fashion, whereas before
it was overridden by the FETCH count.

src/include/executor/nodeLimit.h

@@ -0,0 +1,25 @@
+/*-------------------------------------------------------------------------
+ *
+ * nodeLimit.h
+ *
+ *
+ *
+ * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * $Id: nodeLimit.h,v 1.1 2000/10/26 21:38:03 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef NODELIMIT_H
+#define NODELIMIT_H
+
+#include "nodes/plannodes.h"
+
+extern TupleTableSlot *ExecLimit(Limit *node);
+extern bool ExecInitLimit(Limit *node, EState *estate, Plan *parent);
+extern int	ExecCountSlotsLimit(Limit *node);
+extern void ExecEndLimit(Limit *node);
+extern void ExecReScanLimit(Limit *node, ExprContext *exprCtxt, Plan *parent);
+
+#endif	 /* NODELIMIT_H */