HLSL: Fix handling arrays of structs in interface blocks In HLSL output, structs in interface blocks are not accessed directly. Rather they get copied from the D3D constant buffer to static structs in the shader header. Fix generating the copy/init code in the header to handle arrays of structs correctly. BUG=angleproject:2084 TEST=angle_end2end_tests Change-Id: If66bd5be3f3570ba591b8b62c5284c06fc83dd45 Reviewed-on: https://chromium-review.googlesource.com/608448 Reviewed-by: Corentin Wallez <cwallez@chromium.org> Reviewed-by: Geoff Lang <geofflang@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>