Hello,

Here are some updates for ARM target:

helper.c
  - copy reference c0_c2 to runtime c0_c2 and not c0_c1

op_helper.c
  - remove old code (PARAM1, probably some left over from old dyngen)
    that broke do_[us]sat

translate.c
  - gen_smul_dual should sign-extend from 16 bit to 32 bit and not from
    8 to 32
  - disas_arm_insn:
    * smlalxy:  that was completely wrong;  now the addition is
      performed as for smlald
    * pkhtb:  optional ASR not taken into account (similar to [us]sat)
    * pkhtb/pkhbt: tmp2 is dead
    * smlald, smlsld, smuad, smusd, smlad, smlsd: rd and rn swapped

Except for the c0_c2 modification, these changes were tested:
  - small unit tests which results were "manually" compared to hardware
  - check FFmpeg now correctly decodes the first frame of a video


Laurent