Rollup of 23 pull requests

Successful merges:

 - #141658 (rustdoc search: prefer stable items in search results)
 - #141828 (Add diagnostic explaining STATUS_STACK_BUFFER_OVERRUN not only being used for stack buffer overruns if link.exe exits with that exit code)
 - #144823 (coverage: Extract HIR-related helper code out of the main module)
 - #144883 (Remove unneeded `drop_in_place` calls)
 - #144923 (Move several more float tests to floats/mod.rs)
 - #144988 (Add annotations to the graphviz region graph on region origins)
 - #145010 (Couple of minor abi handling cleanups)
 - #145017 (Explicitly disable vector feature on s390x baseline of bad-reg test)
 - #145027 (Optimize `char::is_alphanumeric`)
 - #145050 (add member constraints tests)
 - #145073 (update enzyme submodule to handle llvm 21)
 - #145080 (Escape diff strings in MIR dataflow graphviz)
 - #145082 (Fix some bad formatting in `-Zmacro-stats` output.)
 - #145083 (Fix cross-compilation of Cargo)
 - #145096 (Fix wasm target build with atomics feature)
 - #145097 (remove unnecessary `TypeFoldable` impls)
 - #145100 (Rank doc aliases lower than equivalently matched items)
 - #145103 (rustc_metadata: remove unused private trait impls)
 - #145115 (defer opaque type errors, generally greatly reduce tainting)
 - #145119 (rustc_public: fix missing parenthesis in pretty discriminant)
 - #145124 (Recover `for PAT = EXPR {}`)
 - #145132 (Refactor map_unit_fn lint)
 - #145134 (Reduce indirect assoc parent queries)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup of 23 pull requests

Successful merges:

 - #141658 (rustdoc search: prefer stable items in search results)
 - #141828 (Add diagnostic explaining STATUS_STACK_BUFFER_OVERRUN not only being used for stack buffer overruns if link.exe exits with that exit code)
 - #144823 (coverage: Extract HIR-related helper code out of the main module)
 - #144883 (Remove unneeded `drop_in_place` calls)
 - #144923 (Move several more float tests to floats/mod.rs)
 - #144988 (Add annotations to the graphviz region graph on region origins)
 - #145010 (Couple of minor abi handling cleanups)
 - #145017 (Explicitly disable vector feature on s390x baseline of bad-reg test)
 - #145027 (Optimize `char::is_alphanumeric`)
 - #145050 (add member constraints tests)
 - #145073 (update enzyme submodule to handle llvm 21)
 - #145080 (Escape diff strings in MIR dataflow graphviz)
 - #145082 (Fix some bad formatting in `-Zmacro-stats` output.)
 - #145083 (Fix cross-compilation of Cargo)
 - #145096 (Fix wasm target build with atomics feature)
 - #145097 (remove unnecessary `TypeFoldable` impls)
 - #145100 (Rank doc aliases lower than equivalently matched items)
 - #145103 (rustc_metadata: remove unused private trait impls)
 - #145115 (defer opaque type errors, generally greatly reduce tainting)
 - #145119 (rustc_public: fix missing parenthesis in pretty discriminant)
 - #145124 (Recover `for PAT = EXPR {}`)
 - #145132 (Refactor map_unit_fn lint)
 - #145134 (Reduce indirect assoc parent queries)

r? `@ghost`
`@rustbot` modify labels: rollup

Rollup merge of #145115 - lcnr:less-borrowck-tainting, r=compiler-errors

defer opaque type errors, generally greatly reduce tainting

fixes the test for #135528, does not actually fix that issue properly.

This is useful as it causes the migration to #139587 to be a lot easier.