Revert "Remove dynamic indexing of matrices and vectors in HLSL" Seems to be failing a WebGL/ES2 CTS test in D3D9: conformance/ogles/GL/mat3/mat3_001_to_006 BUG=angleproject:1116 BUG=525188 This reverts commit 83f3411da456faac8570892e3dd7d76edf4095e5. Change-Id: Ic186f51240dbdd96ccab3f5470329cdc9727c618 Reviewed-on: https://chromium-review.googlesource.com/295730 Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Jamie Madill <jmadill@chromium.org>