Add a security_barrier option for views.

When a view is marked as a security barrier, it will not be pulled up
into the containing query, and no quals will be pushed down into it,
so that no function or operator chosen by the user can be applied to
rows not exposed by the view.  Views not configured with this
option cannot provide robust row-level security, but will perform far
better.

Patch by KaiGai Kohei; original problem report by Heikki Linnakangas
(in October 2009!).  Review (in earlier versions) by Noah Misch and
others.  Design advice by Tom Lane and myself.  Further review and
cleanup by me.

src/include/nodes/parsenodes.h

@@ -706,6 +706,7 @@ typedef struct RangeTblEntry
 	 * Fields valid for a subquery RTE (else NULL):
 	 */
 	Query	   *subquery;		/* the sub-query */
+	bool		security_barrier;	/* subquery from security_barrier view */
 
 	/*
 	 * Fields valid for a join RTE (else NULL/zero):
@@ -1208,6 +1209,7 @@ typedef enum AlterTableType
 	AT_SetTableSpace,			/* SET TABLESPACE */
 	AT_SetRelOptions,			/* SET (...) -- AM specific parameters */
 	AT_ResetRelOptions,			/* RESET (...) -- AM specific parameters */
+	AT_ReplaceRelOptions,		/* replace reloption list in its entirety */
 	AT_EnableTrig,				/* ENABLE TRIGGER name */
 	AT_EnableAlwaysTrig,		/* ENABLE ALWAYS TRIGGER name */
 	AT_EnableReplicaTrig,		/* ENABLE REPLICA TRIGGER name */
@@ -2277,6 +2279,7 @@ typedef struct ViewStmt
 	List	   *aliases;		/* target column names */
 	Node	   *query;			/* the SELECT query */
 	bool		replace;		/* replace an existing view? */
+	List	   *options;		/* options from WITH clause */
 } ViewStmt;
 
 /* ----------------------