Auto merge of #102318 - Amanieu:default_alloc_error_handler, r=oli-obk

Stabilize default_alloc_error_handler

Tracking issue: #66741

This turns `feature(default_alloc_error_handler)` on by default, which causes the compiler to automatically generate a default OOM handler which panics if `#[alloc_error_handler]` is not provided.

The FCP completed over 2 years ago but the stabilization was blocked due to an issue with unwinding. This was fixed by #88098 so stabilization can be unblocked.

Closes #66741

diff --cc compiler/rustc_error_messages/locales/en-US/metadata.ftl
Simple merge

diff --cc compiler/rustc_feature/src/accepted.rs
Simple merge

diff --cc compiler/rustc_feature/src/active.rs
Simple merge

diff --cc compiler/rustc_metadata/src/creader.rs
Simple merge

diff --cc compiler/rustc_metadata/src/errors.rs
Simple merge