load/store instruction format ... now generates load/store code

load/store instruction format ... now generates load/store code
and breaks it into a separate EA and MemAccess templated
from how the Alpha ARch. was coded to do the same thing.

arch/mips/isa/bitfields.isa:
    comment change
arch/mips/isa/decoder.isa:
    re-structuring of load/store instruction definitions
arch/mips/isa/formats/mem.isa:
    Define LoadMemory & Store Memory formats
    Use style of formatting & base class similar to what was used for ALPHA
arch/mips/isa/formats/util.isa:
    Insert LoadStoreBase function here from alpha/arch/isa/mem.isa
arch/mips/isa/operands.isa:
    change shw->sh and uhw->uh

--HG--
extra : convert_revision : 5d85f15f4a600dd4c473a3b4a170ba39cf07fc8a