- Also enables 6 new tests in LineLoopTests.cpp in angle_end2end

Bug: angleproject:2458

Change-Id: I4aec12b0ac780e81e6811f1199a5acaf17d9b982
Reviewed-on: https://chromium-review.googlesource.com/1010411Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Luc Ferron <lucferron@chromium.org>