Fixes for Paired-Single FP Compare Operations...

Fixes for Paired-Single FP Compare Operations...
Now all the variations of FP should be implemented correctly in the decoder.
The new formats and functions supporting these functions need to be implemented for
some of the FP stuff but for the most part things are looking like their "supposed to"...

arch/mips/isa/decoder.isa:
    Fixes for Paired-Single FP Compare Operations...
    Now all the variations of FP should be implemented correctly in the decoder.
arch/mips/isa/formats/fp.isa:
    Add new PS formats
arch/mips/isa_traits.cc:
    Add skeleton overloaded round & truncate functions
arch/mips/isa_traits.hh:
    declare overloaded functions

--HG--
extra : convert_revision : 15d5cf7b08ac2dc9ebcd6b268e92d4abffdd8597