PR gold/10708
* copy-relocs.cc (Copy_relocs::emit_copy_reloc): Hold a lock on the
object when reading from the file.
* gold.cc (queue_middle_tasks): Hold a lock on the object when doing
second layout pass.
* icf.cc (preprocess_for_unique_sections): Hold a lock on the object
when reading section contents.
(get_section_contents): Likewise.
(icf::find_identical_sections): Likewise.
* mapfile.cc (Mapfile::print_discarded_sections): Hold a lock on the
object when reading from the file.
* plugin.cc (Plugin_manager::layout_deferred_objects): Hold a lock on
the object when doing deferred section layout.