Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

When an asm location cannot be resolved to a function the cost
will be spread as small value and then filtered by the threshold.
As a first step solution display the number of event that cannot
be resolved as a valid function location.

MFC after: 1week

Improve "top" header by:
- Display sample received per PMCs (or merged PMCs).
- Display percentage vs all samples

- Reorganize code in 'plugin' to share log processing.
- Kcachegrind (calltree) support with assembly/source
code mapping and call count estimator (-F).
- Top mode for calltree and callgraph plugin (-T).

MFC after: 1 month