add regression test for stale fLastMoveToIndex

This test used to assert/fail under ASAN because copyPath's
fLastMoveToIndex was garbage after the internal copy (in SkPath::transform).
Now the code sets it to the src's value.

Bug:883596
Change-Id: I3cba82fb63398bf4aa0abc9d3f2a0067d8ad9006
Reviewed-on: https://skia-review.googlesource.com/c/178931
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Mike Reed <reed@google.com>
1 file changed