Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Merge remote-tracking branch 'remotes/kevin/tags/for-upstream' into staging

Multiboot patches

# gpg: Signature made Wed 21 Mar 2018 14:38:36 GMT
# gpg:                using RSA key 7F09B272C88F2FD6
# gpg: Good signature from "Kevin Wolf <kwolf@redhat.com>"
# Primary key fingerprint: DC3D EB15 9A9A F95D 3D74  56FE 7F09 B272 C88F 2FD6

* remotes/kevin/tags/for-upstream:
  tests/multiboot: Add .gitignore
  tests/multiboot: Add tests for the a.out kludge
  tests/multiboot: Test exit code for every qemu run
  multiboot: Check validity of mh_header_addr
  multiboot: Reject kernels exceeding the address space

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