UefiCpuPkg: Using the "movabsq" instruction to read global variable mDoFarReturnFlag and mErrorCodeFlag to avoid page fault with big RAM sizes (> 2GB).

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jeff Fan <jeff.fan@intel.com>



git-svn-id: svn://svn.code.sf.net/p/edk2/code/trunk/edk2/UefiCpuPkg@14920 6f19259b-4bc3-4df7-8a09-765794883524