Filter by instruction pointer

Intel PT provides the ability to filter a trace by instruction pointer range. I can imagine using someone wanting to include only specific files, libraries, or functions in a trace. People could trace long time periods and collect data for only particularly problematic regions of code.

I'm not sure how flexible these filters are, whoever does this will need to play around with `perf record --filter` a bit to figure out what it can do.

Start by experimenting with `perf record --filter` to establish which instruction-pointer range filters Intel PT supports. No files or tests are named; completion would require defining the supported filtering behavior, integrating it into magic-trace, and verifying that traces can be limited to the selected code regions.

Written by the indexing model from the issue text.