* mipsnbsd-nat.c (mipsnbsd_fetch_inferior_registers)
(mipsnbsd_store_inferior_registers): Use get_regcache_arch to get at
the current architecture. Update call to getregs_supplies.
(getregs_supplies): Add gdbarch as parameter and replace
current_gdbarch.
* mipsnbsd-tdep.c (mipsnbsd_get_longjmp_target): Use get_frame_arch to
get at the current architecture. Update call to NBSD_MIPS_JB_OFFSET and
NBSD_MIPS_JB_ELEMENT_SIZE.
(NBSD_MIPS_JB_ELEMENT_SIZE, NBSD_MIPS_JB_OFFSET): Add gdbarch and
replace current_gdbarch.
* remote-mips.c (mips_map_regno): Add gdbarch as parameter and replace
current_gdbarch.
(mips_fetch_registers, mips_store_registers): Update call
to mips_map_regno.
(mips_load): Use get_regcache_arch to get at the current_architecture
and replace current_gdbarch.