The kallsyms is huge (like 12Mb) and we want to avoid adding anything we
don't need. Instead, we can rely on the symbols source to decode the
symbols immediately and add them to supplemental.
As we gain in usage, we need to be more careful about using a prefix
that will not collide with other symbols. So version 3 of our ABI will
change to using Sysprof/SYSPROF/sysprof as the various prefixes.
The soname/api version bump will happen later on this branch so that
things are easier to test up until then.
