Adding an <info> tag?

[David Malcolm]

Currently we have two kinds of result within an <analysis>:
  * <issue> elements, representing a warning from an analysis code about
a possible problem with the software-under-test (SUT)
  * <failure> elements, representing a report about a failure of an
analysis tool to achieve full coverage of the SUT (e.g. the tool crashed
or timed out)

I'm thinking it might be useful to be able for an analyzer to record
arbitrary extra information about the software-under-test, where it
isn't an issue as such, but for custom data-gathering about the SUT, so
I'm considering adding an <info> element as a third type of result, with
an optional <location> and allowing storing <custom-fields>.

The motivating use-case for me is in my mass-analysis of Python
extension modules: I though it might be interesting to gather some stats
on uses of the CPython API, and it's not a bit stretch to add this to
cpychecker's firehose output.   Perhaps one could use this to build an
lxr-style indexing tool also.

Thoughts?
Dave