Patch 960/1 (Peter Teichmann):
   NWFPE patch to be more compliant to IEEE-754

1. The RND/URD instruction was handled as int_to_float(float_to_int
   (number)) which is wrong because it only works for floating point
   numbers that fit in an integer.

2. The FLT instruction was setting the rounding precision for
   extended precision calculations, which is not necessary
   (probably a historic relict) but has undesirable side effects
   on all extended precision calculations.