Add GL_ARM_shader_framebuffer_fetch builtins Bug: b/242419750 Bug: angleproject:7882 Change-Id: I85582ad21e58e448b740789ec88f783c8b95ee01 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4189028 Reviewed-by: Cody Northrop <cnorthrop@google.com> Commit-Queue: Sean Risser <srisser@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>