Modified the x86 KVM-in-SE syscall handler to flush the TLB following
each syscall, in case the page table has been modified. This is done
by reloading the value in %cr3. Doing this requires an intermediate
GPR, which we store in a new scratch buffer following the syscall code
at address `syscallDataBuf`.
GitHub issue: https://github.com/gem5/gem5/issues/409
Change-Id: Ibc20018c97ebb1794fa31a0c71e0857d661c7c9d
7a0e84d853