Remove 'func_tlist' from Func expression nodes, likewise 'param_tlist'

from Param nodes, per discussion a few days ago on pghackers.  Add new
expression node type FieldSelect that implements the functionality where
it's actually needed.  Clean up some other unused fields in Func nodes
as well.
NOTE: initdb forced due to change in stored expression trees for rules.

src/include/nodes/makefuncs.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2000, PostgreSQL, Inc
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $Id: makefuncs.h,v 1.24 2000/04/12 17:16:40 momjian Exp $
+ * $Id: makefuncs.h,v 1.25 2000/08/08 15:42:59 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -18,9 +18,7 @@
 
 extern Oper *makeOper(Oid opno,
 		 Oid opid,
-		 Oid opresulttype,
-		 int opsize,
-		 FunctionCachePtr op_fcache);
+		 Oid opresulttype);
 
 extern Var *makeVar(Index varno,
 		AttrNumber varattno,
@@ -34,8 +32,6 @@ extern Resdom *makeResdom(AttrNumber resno,
 		   Oid restype,
 		   int32 restypmod,
 		   char *resname,
-		   Index reskey,
-		   Oid reskeyop,
 		   bool resjunk);
 
 extern Const *makeConst(Oid consttype,