Final testing fixes for 4.0

  - various CI tweaks and fixes
  - fixes for some tcg tests
  - addition of system tcg tests

# gpg: Signature made Tue 12 Mar 2019 17:07:24 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-testing-for-4.0-120319-1: (26 commits)
  .travis.yml: add softmmu check-tcg tests
  .travis.yml: separate softfloat from check-tcg
  tests/tcg/arm: account for pauth randomness
  tests/tcg/i386: add memory test to exercise softmmu
  tests/tcg/i386: add system mode Hello World test
  tests/tcg: provide a minilib for system tests
  tests/tcg: enable cris base user-mode tests
  tests/tcg/cris: align mul operations
  tests/tcg/cris: comment out the ccs test
  tests/tcg: split cris tests into bare and libc directories
  tests/tcg/cris: cleanup sys.c
  tests/docker: add fedora-cris-cross compilers
  tests/tcg/arm: add ARMv6-M UNDEFINED 32-bit instruction test
  tests/tcg/xtensa: enable system tests
  tests/docker: add debian-xtensa-cross image
  tests/tcg/mips: fix hello-mips compilation
  tests/tcg: add gdb runner variant
  tests/tcg: split run-test into user and system variants
  tests/tcg: add QEMU_OPT option for test runner
  tests/tcg: enable tcg tests for softmmu
  ...
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>