This patch adds the additional transform feedback rules required in
EXT_geometry_shader. In this extension, more draw commands and render
primitives are allowed for transform feedback.

BUG=angleproject:1941
TEST=dEQP-GLES31.functional.geometry_shading.vertex_transform_feedback.*
     angle_end2end_tests

Change-Id: Iedc27dca5c24ca45cd4226a1a0066107c0b40e1d
Reviewed-on: https://chromium-review.googlesource.com/1055192Reviewed-by: Jiajia Qin <jiajia.qin@intel.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Jiawei Shao <jiawei.shao@intel.com>