… in typeck

This computes the same result with less code by computing many of
the old checks at once:

* It won't enter the loop if clength > length, because then the
  result of length - clength will be negative and the
  loop conditional will fail.
* i + clength will never be greater than length, because it
  starts out as i = length - clength, implying that i + clength
  equals length, and it only goes down from there.
* The aborted variable is replaced with control flow.

The search sorting code already sorts by item type discriminant,
putting things with smaller discriminants first. There was
also a special case for sorting keywords and primitives earlier,
and this commit removes it by giving them lower discriminants.

The sorting code has another criteria where items with descriptions
appear earlier than items without, and that criteria has higher
priority than the item type. This shouldn't matter, though,
because primitives and keywords normally only appear in the
standard library, and it always gives them descriptions.

Add VarDebugInfo to Stable MIR

Previously we omitted `VarDebugInfo` because we didn't have `Projection` now that rust-lang#117517 is merged it's possible to add `VarDebugInfo` information in `Body`. This PR adds stable version of the `VarDebugInfo` to `Body`

r? ```@celinval```

…-2, r=GuillaumeGomez

rustdoc-search: simplify `checkPath` and `sortResults`

These two commits reduce the amount of code in search.js with no noticeable change in performance.

https://notriddle.com/rustdoc-html-demo-5/profile-5/index.html

…=aliemjay

Document `DefiningAnchor` a bit more

r? types

…e, r=aliemjay

Don't ICE when ambiguity is found when selecting `Index` implementation in typeck

Fixes rust-lang#118111

The problem here is when we're manually "selecting" an impl for `base_ty: Index<?0>`, we don't consider placeholder region errors (leak check) or ambiguous predicates. Those can lead to us not actually emitting any fulfillment errors on line 3131.

Remove quotation from filename in stable_mir

Previously we had quotation marks in filenames which is obviously wrong this fixes that.

r? ```@celinval```