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

Tracing pull request

* remotes/stefanha/tags/tracing-pull-request:
  virtio-rng: add some trace events
  trace: add some tcg tracing support
  trace: teach lttng backend to use format strings
  trace: [tcg] Include TCG-tracing header on all targets
  trace: [tcg] Include event definitions in "trace.h"
  trace: [tcg] Generate TCG tracing routines
  trace: [tcg] Include TCG-tracing helpers
  trace: [tcg] Define TCG tracing helper routine wrappers
  trace: [tcg] Define TCG tracing helper routines
  trace: [tcg] Declare TCG tracing helper routines
  trace: [tcg] Add 'tcg' event property
  trace: [tcg] Argument type transformation machinery
  trace: [tcg] Argument type transformation rules
  trace: [tcg] Add documentation
  trace: install simpletrace SystemTap tapset
  simpletrace: add simpletrace.py --no-header option
  trace: add tracetool simpletrace_stap format
  trace: extract stap_escape() function for reuse

Conflicts:
	Makefile.objs