Prefix all PLS enums with "GL_" Bug: angleproject:7279 Change-Id: Ifb4062e502305f4e59546f067d195d1a05fbabe4 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/4095380 Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org> Commit-Queue: Chris Dalton <chris@rive.app> Reviewed-by: Steven Noonan <steven@valvesoftware.com>