DWARF5 spec describes single file split dwarf case (when .dwo sections are in the .o files).
Problem is that LLDB does not work correctly in that case. The issue is that, for example, both .debug_info and .debug_info.dwo
has the same type: eSectionTypeDWARFDebugInfo. And when code searches section by type it might find the regular debug section
and not the .dwo one. It seems can be easily fixed though, patch shows the fix I am suggesting.
Note that currently, clang is unable to produce such output, the patch is on review atm: D52296.
It is still would be possible to use assembler to produce such files though.
But the test case refers to the flag from the review mentioned.