Merge remote-tracking branch 'remotes/riscv/tags/riscv-qemu-2.12-critical-fixes'...

RISC-V: Critical fixes for QEMU 2.12

This series includes changes that are considered release critical,
such as floating point register file corruption under SMP Linux
due to incorrect handling of mstatus.FS.

This workaround will be replaced with a more comprehensive fix
for mstatus.FS handling in QEMU 2.13.

# gpg: Signature made Thu 29 Mar 2018 18:22:42 BST
# gpg:                using DSA key 6BF1D7B357EF3E4F
# gpg: Good signature from "Michael Clark <michaeljclark@mac.com>"
# gpg:                 aka "Michael Clark <mjc@sifive.com>"
# gpg:                 aka "Michael Clark <michael@metaparadigm.com>"
# 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: 7C99 930E B17C D8BA 073D  5EFA 6BF1 D7B3 57EF 3E4F

* remotes/riscv/tags/riscv-qemu-2.12-critical-fixes:
  RISC-V: Workaround for critical mstatus.FS bug

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