Merge remote-tracking branch 'remotes/rth/tags/pull-axp-201508018' into staging

Alpha shadow register optimization

# gpg: Signature made Tue 18 Aug 2015 19:09:41 BST using RSA key ID 4DD0279B
# gpg: Good signature from "Richard Henderson <[email protected]>"
# gpg:                 aka "Richard Henderson <[email protected]>"
# gpg:                 aka "Richard Henderson <[email protected]>"

* remotes/rth/tags/pull-axp-201508018:
  target-alpha: Inline hw_ret
  target-alpha: Inline call_pal
  target-alpha: Use separate TCGv temporaries for the shadow registers

Signed-off-by: Peter Maydell <[email protected]>