Separate parse-analysis for utility commands out of parser/analyze.c

(which now deals only in optimizable statements), and put that code
into a new file parser/parse_utilcmd.c.  This helps clarify and enforce
the design rule that utility statements shouldn't be processed during
the regular parse analysis phase; all interpretation of their meaning
should happen after they are given to ProcessUtility to execute.
(We need this because we don't retain any locks for a utility statement
that's in a plan cache, nor have any way to detect that it's stale.)

We are also able to simplify the API for parse_analyze() and related
routines, because they will now always return exactly one Query structure.

In passing, fix bug #3403 concerning trying to add a serial column to
an existing temp table (this is largely Heikki's work, but we needed
all that restructuring to make it safe).

src/include/parser/parse_utilcmd.h

@@ -0,0 +1,28 @@
+/*-------------------------------------------------------------------------
+ *
+ * parse_utilcmd.h
+ *		parse analysis for utility commands
+ *
+ *
+ * Portions Copyright (c) 1996-2007, PostgreSQL Global Development Group
+ * Portions Copyright (c) 1994, Regents of the University of California
+ *
+ * $PostgreSQL: pgsql/src/include/parser/parse_utilcmd.h,v 1.1 2007/06/23 22:12:52 tgl Exp $
+ *
+ *-------------------------------------------------------------------------
+ */
+#ifndef PARSE_UTILCMD_H
+#define PARSE_UTILCMD_H
+
+#include "parser/parse_node.h"
+
+
+extern List *transformCreateStmt(CreateStmt *stmt, const char *queryString);
+extern List *transformAlterTableStmt(AlterTableStmt *stmt,
+									 const char *queryString);
+extern IndexStmt *transformIndexStmt(IndexStmt *stmt, const char *queryString);
+extern void transformRuleStmt(RuleStmt *stmt, const char *queryString,
+							  List **actions, Node **whereClause);
+extern List *transformCreateSchemaStmt(CreateSchemaStmt *stmt);
+
+#endif   /* PARSE_UTILCMD_H */