Merge "librust_baremetal: statically choose x86_64 memset" into main am: 42992d6413

Original change: https://android-review.googlesource.com/c/platform/bionic/+/3489695

Change-Id: Ie3b3d24d7173d6c58c44be2cfda3502807341f49
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>