Move exprType(), exprTypmod(), expression_tree_walker(), and related routines
Tom Lane <tgl@sss.pgh.pa.us>
Move exprType(), exprTypmod(), expression_tree_walker(), and related routines into nodes/nodeFuncs, so as to reduce wanton cross-subsystem #includes inside the backend. There's probably more that should be done along this line, but this is a start anyway.