[MLton] Building MLton

[Daniel C. Wang]

I vaguley remember the old Dec Alpha's had an  "32-bit" addressing mode, 
for portablity with 32-bit apps.
This would let you run code that used 32-bit pointers on the alpha with 
just a recompile, but gave you access to the better alpha instructioin set.

Is there a similar option for gcc/linux. I'd suspect using 64-bit 
pointers isn't needed for most MLton code. However, getting access to 
the extra registers and native 64-bit arithmitic would be a win.