Move Trigger and TriggerDesc structs out of rel.h into a new reltrigger.h

This lets us stop including rel.h into execnodes.h, which is a widely
used header.

src/include/utils/reltrigger.h

@@ -0,0 +1,74 @@
+/*-------------------------------------------------------------------------
+ *
+ * reltrigger.h
+ *	  POSTGRES relation trigger definitions.
+ *
+ *
+ * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * src/include/utils/reltrigger.h
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef RELTRIGGER_H
+#define RELTRIGGER_H
+
+
+/*
+ * These struct really belongs to trigger.h, but we put it separately so that
+ * it can be cleanly included in rel.h and other places.
+ */
+
+typedef struct Trigger
+{
+	Oid			tgoid;			/* OID of trigger (pg_trigger row) */
+	/* Remaining fields are copied from pg_trigger, see pg_trigger.h */
+	char	   *tgname;
+	Oid			tgfoid;
+	int16		tgtype;
+	char		tgenabled;
+	bool		tgisinternal;
+	Oid			tgconstrrelid;
+	Oid			tgconstrindid;
+	Oid			tgconstraint;
+	bool		tgdeferrable;
+	bool		tginitdeferred;
+	int16		tgnargs;
+	int16		tgnattr;
+	int16	   *tgattr;
+	char	  **tgargs;
+	char	   *tgqual;
+} Trigger;
+
+typedef struct TriggerDesc
+{
+	Trigger    *triggers;		/* array of Trigger structs */
+	int			numtriggers;	/* number of array entries */
+
+	/*
+	 * These flags indicate whether the array contains at least one of each
+	 * type of trigger.  We use these to skip searching the array if not.
+	 */
+	bool		trig_insert_before_row;
+	bool		trig_insert_after_row;
+	bool		trig_insert_instead_row;
+	bool		trig_insert_before_statement;
+	bool		trig_insert_after_statement;
+	bool		trig_update_before_row;
+	bool		trig_update_after_row;
+	bool		trig_update_instead_row;
+	bool		trig_update_before_statement;
+	bool		trig_update_after_statement;
+	bool		trig_delete_before_row;
+	bool		trig_delete_after_row;
+	bool		trig_delete_instead_row;
+	bool		trig_delete_before_statement;
+	bool		trig_delete_after_statement;
+	/* there are no row-level truncate triggers */
+	bool		trig_truncate_before_statement;
+	bool		trig_truncate_after_statement;
+} TriggerDesc;
+
+
+#endif   /* RELTRIGGER_H */