Also replace some extension enums with core ones.

Bug chromium:805881

Change-Id: I80a9b658fb8dda9c759c4d79b89fbe71b8b91ae1
Reviewed-on: https://swiftshader-review.googlesource.com/16728Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>