Merge remote-tracking branch 'remotes/rth/tags/tcg-sparc-pull-20140428' into staging

TCG sparc backend update for 20140428

# gpg: Signature made Mon 28 Apr 2014 19:36:55 BST using RSA key ID 4DD0279B
# gpg: Can't check signature: public key not found

* remotes/rth/tags/tcg-sparc-pull-20140428:
  tcg-sparc: Accept stores of zero
  tcg-sparc: Fix small 32-bit movi
  tcg-sparc: Fixup function argument types
  tcg-sparc: Hoist common argument loads in tcg_out_op
  tcg-sparc: Don't handle mov/movi in tcg_out_op
  tcg-sparc: Tidy check_fit_* tests
  tcg-sparc: Implement muls2_i32
  tcg-sparc: Use the RETURN instruction
  tcg-sparc: Use 64-bit registers with sparcv8plus
  tcg-sparc: Support trunc_shr_i32
  tcg-sparc: Remove most uses of TCG_TARGET_REG_BITS
  tcg: Add INDEX_op_trunc_shr_i32
  tcg: Fix missed pointer size != TCG_TARGET_REG_BITS changes

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>