Rollup merge of #145484 - Zalathar:archive-builder, r=bjorn3

Remove `LlvmArchiveBuilder` and supporting code/bindings

Switching over to the newer Rust-based `ArArchiveBuilder` happened in rust-lang/rust#128936, a year ago.

Per the comment in `new_archive_builder`, that seems like enough time to justify removing the older, unused `LlvmArchiveBuilder` implementation and its associated bindings.

Fixes rust-lang/rust#128955.

Author: Zalathar