Merge "riscv64: assume fast unaligned access." into main am: 3fb5c15a

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2734373



Change-Id: I05345473ece976678692608c5cac4b22412e5424
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>