PLEASE: no horrible HEAP_SUFFIX junk

[Henry Cejtin]

Please,  get rid of that horrible HEAP_SUFFIX code in the mlton shell script.
Note, it isn't used at all, thank god  (the  shell  variable  HEAP_SUFFIX  is
defined  but  not  used)  and  it is incredibly ugly and stupid.  Just delete
everything from the definition of HEAP_SUFFIX through the commented out `fi'.
It  is  so  much  nicer  that  way.  If some goofy person wants to try to use
SML/NJ to compile MLton on a non-Linux box, they are going to  need  to  know
all  kinds  of  things.   The ability to change the dumped heap suffix is the
least of their worries.  It isn't worth uglifying  the  MLton  script,  which
doesn't even use SML/NJ, just in this odd case.