The following line was added by the translator to work around a
swiftshader bug where no gl_PerVertex declaration (and hence no
gl_Position) would fail an assertion:

    gl_Position = gl_Position;

The swiftshader bug is fixed, so this line can be removed.

Bug: b/176161380
Change-Id: I68a8e0d9cd8b97e9d294a119c2daa4ab64ec863f
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2633729Reviewed-by: Tim Van Patten <timvp@google.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@chromium.org>