Merge remote-tracking branch 'remotes/palmer/tags/riscv-for-master-4.0-rc1' into...

A Single RISC-V Patch for 4.0-rc1

If this is too late I'm OK with it being in rc2, but it fixes a concrete
regression and nobody has complained yet so I'd prefer it to be in rc1
if possible.

The fix is to zero-extend the inputs to DIVUW and REMUW, which was
exposed by the GCC test suite.

# gpg: Signature made Tue 26 Mar 2019 05:54:20 GMT
# gpg:                using RSA key 00CE76D1834960DFCE886DF8EF4CA1502CCBAB41
# gpg:                issuer "palmer@dabbelt.com"
# gpg: Good signature from "Palmer Dabbelt <palmer@dabbelt.com>" [unknown]
# gpg:                 aka "Palmer Dabbelt <palmer@sifive.com>" [unknown]
# gpg: WARNING: This key is not certified with a trusted signature!
# gpg:          There is no indication that the signature belongs to the owner.
# Primary key fingerprint: 00CE 76D1 8349 60DF CE88  6DF8 EF4C A150 2CCB AB41

* remotes/palmer/tags/riscv-for-master-4.0-rc1:
  target/riscv: Zero extend the inputs of divuw and remuw

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