Update of CPUID macros to fix segfaults in amd64 code.
Update of CPUID macros to fix segfaults in amd64 code.

cjntaylor/eigen,pthulhu/eigen,cjntaylor/eigen,cjntaylor/eigen,pthulhu/eigen,pthulhu/eigen,cjntaylor/eigen,pthulhu/eigen,pthulhu/eigen