[ELF] Avoid adding an orphan section to a less suitable segment

If segments are defined in a linker script, placing an orphan section
before the found closest-rank section can result in adding it in a
previous segment and changing flags of that segment. This happens if
the orphan section has a lower sort rank than the found section. To
avoid that, the patch forces orphan sections to be moved after the
found section if segments are explicitly defined.

Differential Revision: https://reviews.llvm.org/D111717