MIPS rehosting work
Implement support for TCG's setcond uop in S2E.
Create memory region for the flash before calling load_image_targphys.
Fix S2E implementation of TCG op DIV2, needed for MIPS.
Add last_block_pc to PANDA API
Add JSON device parsing and initialization to MIPS dummy
Rehosting: allow snapshot to be deferred until arbitrary basic block
Update last basic block in rehosting
rehosting: invalidate the block so llvmtrace can work