* elfxx-mips.c: Include libiberty.h.
(elf_mips_isa, _bfd_mips_elf_mach_extends_p): Remove.
(mips_set_isa_flags): New function, split out from...
(_bfd_mips_elf_final_write_processing): ...here. Only call
mips_set_isa_flags if the EF_MIPS_MACH bits are clear.
(mips_mach_extensions): New array.
(mips_32bit_flags_p): New function.
(_bfd_mips_elf_merge_private_bfd_data): Rework architecture checks.
Use mips_32bit_flags_p to check if one binary is 32-bit and the
other is 64-bit. When adopting IBFD's architecture, adopt the
bfd_mach as well as the flags.
ld/testsuite/
* ld-mips-elf/jr.s: New file.
* ld-mips-elf/mips-elf-flags.exp: New test.
