* coff-mips.c (mips_howto_table): Add entry for MIPS_R_SWITCH.
(mips_ecoff_swap_reloc_in): For MIPS_R_SWTICH, copy r_symndx into
r_offset and set r_symndx to RELOC_SECTION_TEXT.
(mips_ecoff_swap_reloc_out): For MIPS_R_SWITCH, get the r_symndx
value from the r_offset field.
(mips_adjust_reloc_in): Maximum r_type value is now MIPS_R_SWITCH.
For MIPS_R_SWITCH, copy the r_offset field into the addend field.
(mips_adjust_reloc_out): For MIPS_R_SWITCH, copy the addend field
into the r_offset field.
(mips_switch_reloc): New function.
(mips_bfd_reloc_type_lookup): Translate BFD_RELOC_GPREL32 into
MIPS_R_SWITCH.
(mips_relocate_section): Handle MIPS_R_SWITCH.
(mips_relax_section): Adjust MIPS_R_SWITCH offset if necessary.