Removed several "#if BX_CPU_LEVEL < 2" clauses, since stack64.cc   is only compiled for x86-64.
Removed several "#if BX_CPU_LEVEL < 2" clauses, since stack64.cc
  is only compiled for x86-64.

dariaphoebe/bochs,dariaphoebe/bochs,dbrashear/bochs,dariaphoebe/bochs,dbrashear/bochs,dbrashear/bochs,dbrashear/bochs,dariaphoebe/bochs,dbrashear/bochs,dariaphoebe/bochs