Add std patch am: 8338d495f5 am: c0ae144f24

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/unicode-segmentation/+/1547935

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I3813239cf426c823ddf3f915a29b9789736d4b54