Use the type cache for the types used in the emulated GLSL functions. BUG=angleproject:1044 Change-Id: I7c4bde80448b2cd64921b809a3a0dfb37c4e0f47 Reviewed-on: https://chromium-review.googlesource.com/286643 Reviewed-by: Jamie Madill <jmadill@chromium.org> Reviewed-by: Corentin Wallez <cwallez@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>