Commit 240ce26a broke MIPS16 and microMIPS support as it didn't
care those branches and jumps don't have delay slot in
MIPS16 and microMIPS.

This patch introduces a new argument delayslot_size to the
gen_compute_branch() indicating size of delay slot {0, 2, 4}.
And the information is used to call handle_delay_slot() forcingly
when no delay slot is required.

There are some microMIPS branch and jump instructions that requires
exact size of instruction in the delay slot. For indicating
these instructions, MIPS_HFLAG_BDS_STRICT flag is introduced.

Those fictional branch opcodes defined to support MIPS16 and
microMIPS are no longer needed.
Signed-off-by: NYongbok Kim <yongbok.kim@imgtec.com>
Tested-by: NJonas Gorski <jogo@openwrt.org>
Reviewed-by: NLeon Alrae <leon.alrae@imgtec.com>
[leon.alrae@imgtec.com: cosmetic changes]
Signed-off-by: NLeon Alrae <leon.alrae@imgtec.com>