SkSL IR normalization: Convert while loops to for loops

Bug: skia:11095
Change-Id: Icd69df40675e5ecde5004e04a7dcd78eedf8343c
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/344765
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Mike Klein <mtklein@google.com>
21 files changed