simplified SkSL REHYDRATE=0

Change-Id: I653716df5e93dc5c520309729712a78e750a2790
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/307696
Reviewed-by: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
11 files changed