Re: Representation of redirected line pointers in HOT

What I'm thinking is that we should instead do this by extending the use
of the lp_flags field.  lp_flags is two bits, which we currently define
as independent LP_USED and LP_DELETE bits, but in fact LP_DELETE is
never used in heap pages.  (It is used in indexes.)  I propose that
we redefine lp_flags as having four states, say

        LP_UNUSED       0
        LP_NORMAL       1
        LP_REDIRECT     2
        LP_DEAD         3