Change from std to skstd for aligned_union_t

Change-Id: I67bd77cf072e203f23ffc49d591cb826fed598dd
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/258640
Commit-Queue: Herb Derby <herb@google.com>
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Herb Derby <herb@google.com>
Reviewed-by: Ben Wagner <bungeman@google.com>
2 files changed