Rollup merge of #135860 - fmease:compiler-mv-obj-save-dyn-compat-ii, …

…r=jieyouxu

Compiler: Finalize dyn compatibility renaming

Update the Reference link to use the new URL fragment from rust-lang/reference#1666 (this change has finally hit stable). Fixes a FIXME.

Follow-up to #130826.
Part of #130852.

~~Blocking it on #133372.~~ (merged)

r? ghost