Fix compilation of generic renderer DrawGauge() in non-PCH build.

Include "wx/msw/wrapwin.h" explicitly to get the declaration of MulDiv()
needed since the changes of r77748.

Closes #16577.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@77882 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775