Refactor defining emulated functions in BuiltInFunctionEmulator This removes the fixed enumeration of emulated functions in favor of a dynamic map. This makes the code more compact and flexible. The main benefit is that maintaining the list emulated functions is a lot simpler now. Change-Id: Ic9951a496b9f021c76ad5b4c3daccd89af5ac093 Reviewed-on: https://chromium-review.googlesource.com/239871 Tested-by: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Nicolas Capens <capn@chromium.org>