merge (ghc-5-02-branch --> HEAD):

Bugfix: there was an implicit assumption that the list of slots passed
to freeStackSlots was already sorted, whereas in fact this wasn't the
case for at least one call.  Now we explicitly sort the list in
freeStackSlots, removing the hidden assumption.

The symptoms of this bug include crashes (perhaps the "AsmCodeGen"
crash), and a tendency to grow the stack a lot when let-no-escapes are
involved (because the bug caused fragmentation of the stack free list,
so we weren't re-using free slots properly).
  1.17.2.1  +3 -2      fptools/ghc/compiler/codeGen/CgStackery.lhs


ASSERT that the list of stack slots we calculate in buildLivenessMask
is sorted, because we rely on that property later.
  1.38.2.1  +5 -6      fptools/ghc/compiler/codeGen/CgBindery.lhs