alpha return address patch

[Jason Merrill]

>>>>> Richard Henderson <rth@cygnus.com> writes:

> [ Hmm.  This was apparently lost in the mail.  Try again.  ]
> This properly implements REUTRN_ADDR_RTX.  It does it in a way
> I don't like -- via elimination to the stack -- to coddle to the
> needs of the current -fno-sjlj-exceptions code.

I don't think using RETURN_ADDR_RTX should force the return address into
the stack; the current code should be able to handle having the return
address in a register just fine.

Jason