Structure/Union Return Values

[Dan Franklin]

Re copying a structure by having the caller pass a pointer to the
receiving structure down to the callee: the new IBM RT PC does this too.
Note that this means you MUST declare structure-returning functions
as such everywhere you call them, even if you are not using the
structure.  It was considered a small price to pay to make structure
copying truly reentrant, not to mention more efficient.

	Dan Franklin