Rollup merge of #123474 - jieyouxu:issue-7349-port, r=Mark-Simulacrum

Port `run-make/issue-7349` to a codegen test

The test does not need to be a run-make test, it can use the codegen test infrastructure.

Also took the opportunity to rename the test to `no-redundant-item-monomorphization` so it's not just some opaque issue number.

Part of #121876.

Author: GuillaumeGomez