patch applied (ghc-6.6/ghc): When debugging, have the allocator help us a bit

[Ian Lynagh]

Mon Dec 11 04:49:50 PST 2006  Ian Lynagh <igloo at earth.li>
  * When debugging, have the allocator help us a bit
  We now check for freeing memory that isn't allocated, and overwrite memory
  we are about to free with 0xaa.
  It might be nice to also have a flag to control whether the memory
  actually gets free'd.

    M ./rts/RtsStartup.c -2 +14
    M ./rts/RtsUtils.c -2 +109
    M ./rts/RtsUtils.h +3