Mark ab/6881855 as merged am: e135aa3c44 am: cd2ce0a2e0

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/rust/crates/proc-macro-error/+/13111260

Change-Id: Ia61911582cd4d940c83e22b40d1567aca6a2d90a