Bug 1631778 - Only optimize shaders for expected GL version on each platform r=jrmuizel
Bug 1631778 - Only optimize shaders for expected GL version on each platform r=jrmuizel

The full set of optimized shaders can be quite large, so only optimize
for the GL version we expect to be used on the target platform. That
is GLES on Android and Windows (where we presume ANGLE is being used),
and GL elsewhere.

If a different GL version is used we will simply fall back to the
unoptimized shaders.

Depends on D71905

Differential Revision: https://phabricator.services.mozilla.com/D71945

[ghsync] From https://hg.mozilla.org/mozilla-central/rev/55f13e03d6fa6b203f64b60a4730cdaddb496f65

servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender,servo/webrender