moved SkSL BoolLiteral data into IRNode

Change-Id: I177b6daf4d6cb024ba20264ab01d0aa68e768a6d
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/319782
Reviewed-by: John Stiles <johnstiles@google.com>
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
13 files changed