* elf-eh-frame.c (make_pc_relative): New function.
(_bfd_elf_write_section_eh_frame): Use it.
ld/testsuite/
* ld-mips-elf/eh-frame1-n32.d: Expect PC-relative encodings
to include DW_EH_PE_sdata4.
* ld-mips-elf/eh-frame2-n32.d: Likewise.
* ld-mips-elf/eh-frame1-n64.d: Expect PC-relative encodings
to include DW_EH_PE_sdata8.
* ld-mips-elf/eh-frame2-n64.d: Likewise.
* ld-mips-elf/eh-frame1-n32.d: Expect a warning about .eh_frame_hdr.
Remove duplicate CIEs. Adjust relocation addresses and .eh_frame
offsets accordingly. Do not allow there to be any trailing
R_MIPS_NONE relocations.
* ld-mips-elf/eh-frame1-n64.d: Likewise.
* ld-mips-elf/eh-frame2-n32.d: Likewise.
* ld-mips-elf/eh-frame2-n64.d: Likewise.
(_bfd_elf_discard_section_eh_frame): Use them to interpret the CFA
instructions. If the amount of padding is known, reduce the size
of the CIE or FDE by that amount.