Merge "rust: rust_proc_macro host snapshot support." am: 72cbf588 am:...

Merge "rust: rust_proc_macro host snapshot support." am: 72cbf588 am: 77218bb2 am: 06de3f94 am: a9a8f262

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2042225



Change-Id: I1dba219a530ee1733237705900d0af78c70d6cd4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>