automatically generate clone() methods for SkSL fragment processors

Bug: skia:
Change-Id: Ib7b90f20d2b1558aad14f38f95c7c884e654c96d
Reviewed-on: https://skia-review.googlesource.com/28620
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
20 files changed