Code review for XML patch. Instill a bit of sanity in the location of

the XmlExpr code in various lists, use a representation that has some hope
of reverse-listing correctly (though it's still a de-escaping function
shy of correctness), generally try to make it look more like Postgres
coding conventions.

src/include/nodes/nodes.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2006, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.189 2006/12/21 16:05:16 petere Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/nodes.h,v 1.190 2006/12/24 00:29:20 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -130,6 +130,7 @@ typedef enum NodeTag
 	T_RowCompareExpr,
 	T_CoalesceExpr,
 	T_MinMaxExpr,
+	T_XmlExpr,
 	T_NullIfExpr,
 	T_NullTest,
 	T_BooleanTest,
@@ -140,7 +141,6 @@ typedef enum NodeTag
 	T_RangeTblRef,
 	T_JoinExpr,
 	T_FromExpr,
-	T_XmlExpr,
 
 	/*
 	 * TAGS FOR EXPRESSION STATE NODES (execnodes.h)
@@ -166,10 +166,10 @@ typedef enum NodeTag
 	T_RowCompareExprState,
 	T_CoalesceExprState,
 	T_MinMaxExprState,
+	T_XmlExprState,
 	T_NullTestState,
 	T_CoerceToDomainState,
 	T_DomainConstraintState,
-	T_XmlExprState,
 
 	/*
 	 * TAGS FOR PLANNER NODES (relation.h)