This reverts commit b2f547f4.

Reason for revert: Reverting this CL so that I can revert another CL
that is causing tests to crash (see: http://anglebug.com/5741).  A
glslang change causes tests to fail with internal-linker errors.  The
upstream bug is: https://github.com/KhronosGroup/glslang/issues/2567

Bug: angleproject:5740
Change-Id: I8cde0d6c7004b03c130114af67b791e2871b8459
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2748966Reviewed-by: Ian Elliott <ianelliott@google.com>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>
Commit-Queue: Ian Elliott <ianelliott@google.com>