bigger than 2-gig ready

[Henry Cejtin]

To  make  MLton  work with files bigger than 2 gigabytes, you have to compile
all the C code with the following command line argument:
    -D_FILE_OFFSET_BITS=64
or you can add the line
    #define _FILE_OFFSET_BITS       64
but it must occur BEFORE you #include anything.

This will change the definition of various types from int's to  long  long's.
This changes the result and 2nd argument of lseek for instance.