alpha regression on 920625-1

[Jim Wilson]

	No, the problem is after this.  The read from varargs is fine.  The
	problem comes when the struct must be spilled from the registers it
	was read into.

This is the same problem that is causing Ulrich's glibc builds to fail,
except that it is happening with a union in this case.

Your patch doesn't entirely fix the problem, since structs/unions of 1 word
will still fail.

I think we need to consider reverting some of the recent alias changes,
as they are causing too much trouble.

Jim