Reland "Make the SkSL interpreter opt-in"

This reverts commit b6b966aa43a917f575394cf696f1addc2335678e.

Change-Id: I58c34fc8520384157c5adb0056f3568b8ef1d844
Bug: skia:9230
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/225939
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
4 files changed