Signed vs Unsigned (take 2) (src/backend/storage/ipc/procarray.c)

Hi,

With the recent changes at procarray.c, I take a look in.
msvc compiler, has some warnings about signed vs unsigned.

So.

1. Size_t is weird, because all types are int.
2. Wouldn't it be better to initialize static variables?
3. There are some shadowing parameters.
4. Possible loop beyond numProcs?

- for (size_t pgxactoff = 0; pgxactoff < numProcs; pgxactoff++)
+ for (int pgxactoff = 0; pgxactoff < numProcs; pgxactoff++)

I think no functional behavior changed.
Patch attached.

best regards,
Ranier Vilela