Merge remote-tracking branch 'remotes/lalrae/tags/mips-20150918' into staging

MIPS patches 2015-09-18

Changes:
* fixes for rdhwr, tlbwr, mtc0, recip.fmt, rsqrt.fmt and daui instructions
* removal of MIPS_DEBUG code
* use tcg_gen_extrh_i64_i32()
* improve random tlb index generation in cpu_mips_get_random()
* exception handling improvements to correctly restore icount

# gpg: Signature made Fri 18 Sep 2015 12:15:28 BST using RSA key ID 0B29DA6B
# gpg: Good signature from "Leon Alrae <leon.alrae@imgtec.com>"

* remotes/lalrae/tags/mips-20150918:
  target-mips: improve exception handling
  target-mips: correct MTC0 instruction on MIPS64
  target-mips: add missing restriction in DAUI instruction
  target-mips: fix corner case in TLBWR causing QEMU to hang
  pic32: use LCG algorithm for generated random index of TLBWR instruction
  target-mips: get rid of MIPS_DEBUG_SIGN_EXTENSIONS
  target-mips: get rid of MIPS_DEBUG
  target-mips: Fix RDHWR on CP0.Count
  target-mips: remove wrong checks for recip.fmt and rsqrt.fmt
  target-mips: Use tcg_gen_extrh_i64_i32

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