Implement hyperbolic function support for ESSL 3.00 Emulating arc hyperbolic functions is required on HLSL, where they do not exist natively. For this, BuiltInFunctionEmulator is split into GLSL and HLSL subclasses. The GLSL subclass handles the pre-existing built-in emulation implemented for working around OSX bugs, and the HLSL subclass handles emulating asinh, acosh and atanh on HLSL. BUG=angle:855 Change-Id: I0dfeffb862ac27ba7f9ecf5492ec31d9d952b273 Reviewed-on: https://chromium-review.googlesource.com/236861 Reviewed-by: Nicolas Capens <capn@chromium.org> Reviewed-by: Jamie Madill <jmadill@chromium.org> Tested-by: Olli Etuaho <oetuaho@nvidia.com>