In ObjectFileELF we try to read the .gnu_debuglink section of the ELF
file to determine the name of the debug symbols file. If this section
does not exist, we stop the search. Instead, what we should do is locate
a file with the same name as the ELF binary, which is the default
behavior when there isn't any .gnu_debuglink section present.
Ran check-lldb to make sure this doesn't break anything.