Auto merge of #65240 - michaelwoerister:sp-review-3, r=Mark-Simulacrum

Auto merge of #65240 - michaelwoerister:sp-review-3, r=Mark-Simulacrum

self-profiling: Add events for metadata loading (plus a small dep-tracking optimization)

This PR
- adds self-profiling events related to loading things from crate metadata
- makes the compiler cache the `DepNodeIndex` of upstream crates, so that they don't have to be looked up over and over.

The commits are best reviewed in isolation.

Self-profiling tracking issue: https://github.com/rust-lang/rust/issues/58967

r? @Mark-Simulacrum
cc @wesleywiser