In particular matching on complex types such as strings will cause
deep recursion to happen.

Fixes rust-lang#72933

I wasn't aware items _could_ be fake, so I think having a function
mentioning it could be helpful. Also, I'd need to make this change for
cross-crate intra-doc links anyway, so I figured it's better to make the
refactor separate.

This causes unnecessary calls to `grow` when the allocation would fit
exactly in the remaining space.

They are pointless. No reasonable allocator will be able to satisfy a
`reserve_in_place` request that *doubles* the size of an allocation when
dealing with allocations that are 4 KiB and larger.

Just to be sure, I confirmed on Linux that the `reserve_in_place` calls
never succeed.

(Note however that the `reserve_in_place` call for `DroplessArena::grow`
did occasionally succeed prior to the off-by-one fix in the previous
commit, because we would sometimes do a `reserve_in_place` request for
the chunk's current size, which would trivially succeed!)

Also remove a now-unnecessary `placement` argument.

- Use `len` more consistently for the number of elements in a vector,
  because that's the usual name.
- Use `additional` more consistently for the number of elements we want
  to add, because that's what `Vec::reserve()` uses.
- Use `cap` consistently rather than `capacity`.
- Plus a few other tweaks.

This increases consistency and conciseness.

…ace, r=Amanieu

Remove `RawVec::reserve_in_place`.

And some related clean-ups.

r? @oli-obk

…i-obk

Ensure stack when building MIR for matches

In particular matching on complex types such as strings will cause
deep recursion to happen.

Fixes rust-lang#72933

r? @matthewjasper @oli-obk

…Gomez

Add Item::is_fake for rustdoc

I wasn't aware items _could_ be fake, so I think having a function
mentioning it could be helpful. Also, I'd need to make this change for
cross-crate intra-doc links anyway, so I figured it's better to make the
refactor separate.

…an-DPC

Clean up E0647 explanation

r? @Dylan-DPC

Fix a typo (size of the size)

typo: awailable -> available

Add mailmap entry