Merge remote-tracking branch 'remotes/stefanha-gitlab/tags/tracing-pull-request'...

Merge remote-tracking branch 'remotes/stefanha-gitlab/tags/tracing-pull-request' into staging

Pull request

# gpg: Signature made Mon 01 Feb 2021 15:46:52 GMT
# gpg:                using RSA key 8695A8BFD3F97CDAAC35775A9CA4ABB381AB73C8
# gpg: Good signature from "Stefan Hajnoczi <stefanha@redhat.com>" [full]
# gpg:                 aka "Stefan Hajnoczi <stefanha@gmail.com>" [full]
# Primary key fingerprint: 8695 A8BF D3F9 7CDA AC35  775A 9CA4 ABB3 81AB 73C8

* remotes/stefanha-gitlab/tags/tracing-pull-request:
  trace: update docs with meson build information
  trace: document how to specify multiple --trace patterns
  simpletrace: build() missing 2 required positional arguments
  trace: make the 'log' backend timestamp configurable
  error: rename error_with_timestamp to message_with_timestamp
  trace: add meson custom_target() depend_files for tracetool
  tracetool: also strip %l and %ll from systemtap format strings
  tracetool: fix "PRI" macro decoding
  trace: recommend "log" backend for getting started with tracing
  tracing: convert documentation to rST
  trace: fix simpletrace doc mismerge

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