add SkRRect::readFromMemory() fuzzer

Change-Id: I2102056847efe9e56ba6e8150e0d451bffc8f204
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/309378
Reviewed-by: Ben Wagner <bungeman@google.com>
Reviewed-by: Kevin Lubick <kjlubick@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
2 files changed