In more detail:
The first one is required because otherwise the strange 0xc4 in the
string constant makes the tru64 compiler quite unhappy. (I haven't
looked in detail but I think that without extra flags the tru64 compiler
allows only pure ASCII in string constants).
The second one: in tru64 malloc/calloc/realloc of zero bytes returns
a NULL ptr (quite logical, in a way: you couldn't put anything in a
memory block of zero bytes...). I guess one could be fancier and
add a probe for this feature in Configure.pl, but I was feeling lazy.
A third alternative would be to investigate why would anyone be
allocating zero bytes; this might indicate a more serious error,
depending on what the caller was expecting/intending and what were
they going to do with the result.