Linux-user pull request 20210621

# gpg: Signature made Mon 21 Jun 2021 12:03:53 BST
# gpg:                using RSA key CD2F75DDC8E3A4DC2E4F5173F30C38BD3F2FBE3C
# gpg:                issuer "laurent@vivier.eu"
# gpg: Good signature from "Laurent Vivier <lvivier@redhat.com>" [full]
# gpg:                 aka "Laurent Vivier <laurent@vivier.eu>" [full]
# gpg:                 aka "Laurent Vivier (Red Hat) <lvivier@redhat.com>" [full]
# Primary key fingerprint: CD2F 75DD C8E3 A4DC 2E4F  5173 F30C 38BD 3F2F BE3C

* remotes/vivier2/tags/linux-user-for-6.1-pull-request:
  linux-user: Use public sigev_notify_thread_id member if available
  linux-user: Fix incorrect use of feature-test-macros
  linux-user: Check for ieee128 fpbits in PPC64 HWCAP2 feature list
  tests/tcg/linux-test: Check that sigaction can query SIGKILL/SIGSTOP
  linux-user: Let sigaction query SIGKILL/SIGSTOP
  linux-user: Implement pivot_root
  linux-user/trace-events: fix minor typo in format string
  linux-user: Disable static assert involving __SIGRTMAX if it is missing
  linux-user: Set CF_PARALLEL when mapping shared memory

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