[Swan-dev] style question

[D. Hugh Redelmeier]

In 8b254f86c6740a4eb900e481c9c21e8da745b130
before: the type for a priority was unsigned, 32 bit.

Actual bits within that were allocated and documented.

After: the type was changed to unsigned.  Comments and a passert were 
added to make it clear that the type must be at least 32 bits:

-	uint32_t pmax =
+	/* XXX: assume unsigned >= 32-bits */
+	passert(sizeof(unsigned) >= sizeof(uint32_t));
+
+	unsigned pmax =

Why change this from uint32_t?