Make pmap_copy() more TLB friendly.  Specifically, make it use the kernel's direct map instead of the pmap's recursive mapping to access the lowest level in the page table.
Make pmap_copy() more TLB friendly.  Specifically, make it use the kernel's
direct map instead of the pmap's recursive mapping to access the lowest
level in the page table.

MFC after:	6 weeks

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase