Add IsGP64bit and IsPTR64bit to the list of UnsupportedFeatures of the P5600 scheduling definitions. Also mark some MIPS 64-bit instructions by PTR64 and GPR_64 predicates. This reduces number of "No schedule information for" and "lacks information for" errors in case of marking this scheduler model as complete.
This patch is one of a series of patches. The goal is to make P5600 scheduler model complete and turn on the CompleteModel flag.