fix(tools/perf-flamegraph): Get rid of most 'unknown's r/1310

This makes two main changes:

1) It disables profiling of things that aren't part of the invoked
   process (-a). This isn't particularly useful in most cases because
   it will show things like Chrome's VP9 decoding while you're
   profiling something else.

2) It tells perf about the debug symbol format, which for some reason
   isn't DWARF2 by default.

Change-Id: Ida6a54b74f1ec635fec930db7e2a2aa039dd1443
Reviewed-on: https://cl.tvl.fyi/c/depot/+/1185
Reviewed-by: glittershark <grfn@gws.fyi>
Tested-by: BuildkiteCI

0 files changed, 0 insertions, 0 deletions