Simple FixedDiv that does integer divide instruction with 64 bit dividend and 32 bit divisor to produce 32 bit result.
BUG=250
TEST=math_test
R=dingkai@google.com

Review URL: https://webrtc-codereview.appspot.com/1681006

git-svn-id: http://libyuv.googlecode.com/svn/trunk@736 16f28f9a-4ce2-e073-06de-1de4eb20be90