Improve libjingle's ASSERT and VERIFY macros on Windows.
This change has the effect that when using a debugger, a failing ASSERT/VERIFY will break exactly where the failing expression is and not two callstacks up.
Minidumps (for debug builds) will also have the failing expression at the top of the call stack.

R=xians@webrtc.org, xians

Review URL: https://webrtc-codereview.appspot.com/12929004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6633 4adac7df-926f-26a2-2b94-8c16560cd09d