Move the rest of the validation out of TIntermBinary::promote TIntermBinary::promote now has a single purpose of determining the type resulting from a binary math operation. The TIntermBinary constructor taking the left and right nodes can now also call promote automatically, and promote is made into a private member of TIntermBinary. Validation of binary math operand types is done inside ParseContext. BUG=angleproject:952 TEST=angle_unittests Change-Id: I52a409f680c8d4120b757193972d03aed34c6895 Reviewed-on: https://chromium-review.googlesource.com/372624 Reviewed-by: Jamie Madill <jmadill@chromium.org> Commit-Queue: Olli Etuaho <oetuaho@nvidia.com>