Test vector and matrix scalarization does not affect output Vector and matrix scalarization was turned off because it affects the rendering output. We need to turn it back on in some form for Metal. This test is added to check that rendering output is not affected. Test adapted from WebGL CTS test https://github.com/KhronosGroup/WebGL/pull/3214 Bug: angleproject:6306 Change-Id: Ic1db18920064726761d6168f9dd5111772028598 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/3115013 Commit-Queue: Gregg Tavares <gman@chromium.org> Reviewed-by: Kenneth Russell <kbr@chromium.org>