Merge remote-tracking branch 'remotes/stsquad/tags/pull-fpu-next-260219-1' into staging

Merge remote-tracking branch 'remotes/stsquad/tags/pull-fpu-next-260219-1' into staging

Softloat updates, mostly in preparation for s390x usage

# gpg: Signature made Tue 26 Feb 2019 14:09:34 GMT
# gpg:                using RSA key 6685AE99E75167BCAFC8DF35FBD0DB095A9E2A44
# gpg: Good signature from "Alex Bennée (Master Work Key) <alex.bennee@linaro.org>" [full]
# Primary key fingerprint: 6685 AE99 E751 67BC AFC8  DF35 FBD0 DB09 5A9E 2A44

* remotes/stsquad/tags/pull-fpu-next-260219-1:
  tests/Makefile.include: test all rounding modes of softfloat
  softfloat: Support float_round_to_odd more places
  tests/fp: enable f128_to_ui[32/64] tests in float-to-uint
  tests/fp: add wrapping for f128_to_ui32
  softfloat: Implement float128_to_uint32
  softfloat: add float128_is_{normal,denormal}
  tests: Ignore fp test outputs

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