Change UnwindAssemblyInstEmulation::GetNonCallSiteUnwindPlanFromAssembly so it records

the state of the unwind instructions once the prologue has finished.  If it hits an
early return epilogue in the middle of the function, re-instate the prologue after that
epilogue has completed so that we can still unwind for cases where the flow of control
goes past that early-return.  <rdar://problem/11775059>

Move the UnwindPlan operator== definition into the .cpp file, expand the definition a bit.

Add some casts to a SBCommandInterpreter::HandleCompletion() log statement so it builds without
warning on 64- and 32-bit systems.

llvm-svn: 160337