* ldexp.c (fold_name <LOADADDR>): Use the lma.
* ldlang.h (lang_memory_region_type): Delete old_length. Add
last_os.
* ldlang.c (lang_memory_region_lookup): Init new field.
(lang_reset_memory_regions): Reset new field.
(lang_insert_orphan): Don't set load_base.
(lang_leave_overlay): Likewise.
(lang_size_sections_1): Delete unnecessary code setting lma_region
to region. Correct lma region check.
(lang_do_assignments_1): Rename output_section_statement parm
to current_os. Set lma from previous section in region.