Use a specialized hash function for mangled names The hash values used for looking up built-ins now encode the string length and the location of parentheses as six-bit values, so that we don't need to check for these if the hash matches. This decreases shader_translator binary size on Windows by around 10 KB. BUG=angleproject:2267 BUG=chromium:823856 TEST=angle_unittests Change-Id: If8c28e1c8851750633509ec6273f556e06e91cd1 Reviewed-on: https://chromium-review.googlesource.com/973243 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>