There are lots of functions which are retained for binary compatibility.
Clean these up. Move them to mathom.c, and don't compile for blead?
+=head2 am I hot or not?
+
+The idea of F<pp_hot.c> is that it contains the I<hot> ops, the ops that are
+most commonly used. The idea is that by grouping them, their object code will
+be adjacent in the executable, so they have a greater chance of already being
+in the CPU cache (or swapped in) due to being near another op already in use.
+
+Except that it's not clear if these really are the most commonly used ops. So
+anyone feeling like exercising their skill with coverage and profiling tools
+might want to determine what ops I<really> are the most commonly used. And in
+turn suggest evictions and promotions to achieve a better F<pp_hot.c>.
+
+