Remove handcrafted librustc_demangle_static am: 59b25ff22a am: 0bad300d12

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/rustc-demangle-capi/+/2795153

Change-Id: I935b18c5f0efc460c040400547a116f000c26150
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>