(CMake) Properly determine if we are on a 64bit platform
(CMake) Properly determine if we are on a 64bit platform

--HG--
branch : v1-7

bhlzlx/ogre,bhlzlx/ogre,bhlzlx/ogre,ruleless/ogre,ehsan/ogre,ehsan/ogre,bhlzlx/ogre,ruleless/ogre,ehsan/ogre,bhlzlx/ogre,ehsan/ogre,ruleless/ogre,ruleless/ogre,ruleless/ogre,ruleless/ogre,bhlzlx/ogre,ehsan/ogre