Reland Fixed FL9_3 shaders that use glPointCoord without glPointSize. This change fixes a Shader error on FL9_3 that reports Vertex/Pixel Shader linkage signatures between stages being incompatible when glPointCoord is used without glPointSize. Change-Id: I107d06692c5375c07544038f5f4429c1e8d6e313 Reviewed-on: https://chromium-review.googlesource.com/305395 Tested-by: Cooper Partin <coopp@microsoft.com> Reviewed-by: Geoff Lang <geofflang@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org>