examples: Avoid undefined behavior

When 'int' is 32-bits, "1 << 31" is undefined.  So we avoid that
in these couple example programs.

Bug: 8968
Change-Id: Iacaa28bf46a4006de4aee90de33560911744925e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/206691
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
2 files changed