[MLton] crossMap

[Matthew Fluet]

>> gcc version 4.0 gives the following warning when crossMap is declared as a
>> uchar pointer.
>>
>> gc.c: In function createCardMapAndCrossMap:
>> gc.c:1272: warning: pointer targets in assignment differ in signedness
>> gc.c: In function resizeCardMapAndCrossMap:
>> gc.c:2885: warning: pointer targets in assignment differ in signedness
>> gc.c:2889: warning: pointer targets in passing argument 2 of copy differ in signedness
>>
>> The line 2885 warning should be fixed by declaring oldCrossMap as a uchar
>> pointer, though that simply makes the oldCrossMap argument at line 2889
>> give a warning about different signedness.
>
> I would think these warnings are easily fixed by changing the type of
> oldCrossMap and inserting casts at line 1272 and 2888.  I don't have a
> gcc 4.0 handy, so could you please check and do the commit if it's OK?

The casts suffice.  I've committed it (to CVS).