* mips-tdep.c (mips16_decode_reg_save): Distinguish between
sd and sw instructions correctly.
(heuristic_proc_start): Add support for MIPS16.
(mips16_get_imm, mips16_heuristic_proc_desc,
mips32_heuristic_proc_desc): New helper functions for
heuristic_proc_desc.
(heuristic_proc_desc): Rewrite and reorganize to support MIPS16.
(mips_push_arguments): Don't align small arguments in EABI.
(mips32_skip_prologue): Attempt to shrink code size a little.