Auto merge of #74313 - Manishearth:rollup-b55rn6t, r=Manishearth

Rollup of 8 pull requests

Successful merges:

 - #73354 (Update RELEASES.md for 1.45.0)
 - #73852 (rustdoc: insert newlines between attributes)
 - #73867 (Document the union keyword)
 - #74046 (Fix caching issue when building tools.)
 - #74123 (clean up E0718 explanation)
 - #74147 (rustdoc: Allow linking from private items to private types)
 - #74285 (#71669: add ui, codegen tests for volatile + nearby int intrinsics)
 - #74286 (Added detailed error code explanation for issue E0688 in Rust compiler.)

Failed merges:

r? @ghost