* ldlang.h (enum section_type): Add overlay_section.
* ldlang.c (lang_add_section): Handle flags for overlay_section
as per normal_section.
(lang_size_sections_1): When setting lma, detect overlays by
os->sectype rather than by looking for overlapping vmas.
(lang_enter_overlay_section): Use overlay_section type.
(lang_leave_overlay): Set first overlay section to normal.
ld/testsuite/
* ld-spu/ovl.lnk: Use OVERLAY keyword.
