rr-collect-symbols merges symbols into an rr(1) trace.
The trace in trace-dir must be package, with rrpack, so all relevant files appear in the trace
directory.
Symbols can be extracted from a ZIP file downloaded from url, or from a .build-id directory under path
with the usual structure. path defaults to /usr/lib/debug, thus using any available system debuginfo
files.
The extracted debuginfo files are stored in the trace under a debug subdirectory, in a .build-id
directory with the usual structure.
If a debuginfo file contains a .gnu_debugaltlink section then the referenced file will also be copied, if
it's available, with the same file name as the .debug file, but with a .sup suffix.