fix twinx loads a little bit

fix twinx loads a little bit
bugfixes and demap implementation in tlb
ignore some more differencs for one cycle

src/arch/sparc/isa/formats/mem/blockmem.isa:
    twinx has 2 micro-ops
src/arch/sparc/isa/formats/mem/util.isa:
    fix the fault check for twinx
src/arch/sparc/tlb.cc:
    tlb bugfixes and write demapping code
src/cpu/exetrace.cc:
    don't halt on a couple more instruction (ldx, stx) when things differ
    beacuse of the way tlb faults are handled in legion.

--HG--
extra : convert_revision : 1e156dead6ebd58b257213625ed63c3793ef4b71