Implement gl_PointSize point sprite emulation using D3D11 geometry shaders. TRAC #22412 Signed-off-by: Nicolas Capens Signed-off-by: Shannon Woods Author: Jamie Madill git-svn-id: https://angleproject.googlecode.com/svn/branches/dx11proto@1786 736b8ea6-26fd-11df-bfd4-992fa37f6226