* arm.cc (Arm_outout_section::fix_exidx_coverage): Adjust call to
Output_section::add_relaxed_input_section.
* output.cc (Output_section::add_relaxed_input_section): Add new
arguments LAYOUT and NAME. Set section order index.
(Output_section::convert_input_sections_in_list_to_relaxed_sections):
Copy section order index.
* output.h (Output_section::add_relaxed_input_section): Add new
arguments LAYOUT and NAME.