Classify TSymbols using an enum Symbols can be either built-ins, user-defined, nameless, or for ANGLE's internal use. In addition we currently use TFunction symbols that are not yet resolved - they might later resolve to either a built-in or a user-defined function. Record this information in each TSymbol so that TSymbol contains sufficient information for deciding how to format symbol names in output. The goal is to eventually replace current uses of TName with pointers to different TSymbol objects. So far only built-ins and user-defined symbols have associated TSymbol objects, but that will be expanded to cover ANGLE's internal symbols as well. BUG=angleproject:2267 TEST=angle_unittests Change-Id: I927ce023fe257cc236da82c127700f3bd72bfe96 Reviewed-on: https://chromium-review.googlesource.com/816952 Commit-Queue: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Corentin Wallez <cwallez@chromium.org>