SkRuntimeEffect: Handle different main() signatures on CPU

Bug: skia:10603
Change-Id: Ib4d2b36c09c30a9a112f5a2d2d7060c09009671b
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/309782
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
3 files changed