These links never worked, but the lint was suppressed due to the fact
that the span was pointing into the macro. With the new macro
implementation, the span now points directly to the doc comment in the
macro invocation, so it's no longer suppressed.

The `macro_rules!` implementation was becomng excessively complicated,
and difficult to modify. The new proc macro implementation should make
it much easier to add new features (e.g. skipping certain `#[derive]`s)

Always format to internal String in FmtPrinter

This avoids monomorphizing for different parameters, decreasing generic code
instantiated downstream from rustc_middle -- locally seeing 7% unoptimized LLVM IR
line wins on rustc_borrowck, for example.

We likely can't/shouldn't get rid of the Result-ness on most functions, though some
further cleanup avoiding fmt::Error where we now know it won't occur may be possible,
though somewhat painful -- fmt::Write is a pretty annoying API to work with in practice
when you're trying to use it infallibly.

Partially move cg_ssa towards using a single builder

Not all codegen backends can handle hopping between blocks well. For example Cranelift requires blocks to be terminated before switching to building a new block. Rust-gpu requires a `RefCell` to allow hopping between blocks and cg_gcc currently has a buggy implementation of hopping between blocks. This PR reduces the amount of cases where cg_ssa switches between blocks before they are finished and mostly fixes the block hopping in cg_gcc. (~~only `scalar_to_backend` doesn't handle it correctly yet in cg_gcc~~ fixed that one.)

`@antoyo` please review the cg_gcc changes.

Back more metadata using per-query tables

r? `@ghost`

Rollup of 9 pull requests

Successful merges:

 - #89887 (Change `char` type in debuginfo to DW_ATE_UTF)
 - #94267 (Remove unused ordering derivations and bounds for `SimplifiedTypeGen`)
 - #94270 (Miri: relax fn ptr check)
 - #94273 (add matching doc to errorkind)
 - #94283 (remove feature gate in control_flow examples)
 - #94288 (Cleanup a few Decoder methods)
 - #94292 (riscv32imc_esp_espidf: set max_atomic_width to 64)
 - #94296 (⬆ rust-analyzer)
 - #94300 (Fix a typo in documentation of `array::IntoIter::new_unchecked`)

Failed merges:

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

Fix a typo in documentation of `array::IntoIter::new_unchecked`

🌸

⬆ rust-analyzer

r? `@ghost`

riscv32imc_esp_espidf: set max_atomic_width to 64

For espidf targets without native atomics, there is atomic emulation inside [the newlib component of espidf](https://github.com/espressif/esp-idf/blob/master/components/newlib/stdatomic.c), this has been extended to support emulation up to 64bits therefore we are safe to increase the atomic width for the `riscv32imc_esp_espidf` target.

Closes https://github.com/esp-rs/rust/issues/107

cc: `@ivmarkov`

Cleanup a few Decoder methods

This is just some simple follow up to #93839.

r? `@nnethercote`

remove feature gate in control_flow examples

Stabilization was done in https://github.com/rust-lang/rust/pull/91091, but the two examples weren't updated accordingly.

Probably too late to put it into stable, but it should be in the next release :)

add matching doc to errorkind

Rework of #90706

Miri: relax fn ptr check

As discussed in https://github.com/rust-lang/unsafe-code-guidelines/issues/72#issuecomment-1025407536, the function pointer check done by Miri is currently overeager: contrary to our usual principle of only checking rather uncontroversial validity invariants, we actually check that the pointer points to a real function.

So, this relaxes the check to what the validity invariant probably will be (and what the reference already says it is): the function pointer must be non-null, and that's it.

The check that CTFE does on the final value of a constant is unchanged -- CTFE recurses through references, so it makes some sense to also recurse through function pointers. We might still want to relax this in the future, but that would be a separate change.

r? `@oli-obk`

Remove unused ordering derivations and bounds for `SimplifiedTypeGen`

This is another small PR clearing the way for work on #90317.

Change `char` type in debuginfo to DW_ATE_UTF

Rust previously encoded the `char` type as DW_ATE_unsigned_char. The more appropriate encoding is `DW_ATE_UTF`.

Clang also uses the DW_ATE_UTF for `char32_t` in C++.

This fixes the display of the `char` type in the Windows debuggers. Without this change, the variable did not show in the locals window.
![image](https://user-images.githubusercontent.com/704597/137368067-9b3e4dc8-a075-44ba-a687-bf3810a44e5a.png)

LLDB 13 is also able to display the char value, when before it failed with `need to add support for DW_TAG_base_type 'char' encoded with DW_ATE = 0x8, bit_size = 32`

r? `@wesleywiser`

Reapply cg_llvm: `fewer_names` in `uncached_llvm_type`

r? `@davidtwco` `@erikdesjardins`

Node id to hir id refactor

Related to #89278

r? `@oli-obk`

Co-authored-by: NJosh Triplett <josh@joshtriplett.org>

Rollup of 12 pull requests

Successful merges:

 - #94128 (rustdoc: several minor fixes)
 - #94137 (rustdoc-json: Better Header Type)
 - #94213 (fix names in feature(...) suggestion)
 - #94240 (Suggest calling .display() on `PathBuf` too)
 - #94253 (Use 2021 edition in ./x.py fmt)
 - #94259 (Bump download-ci-llvm-stamp for llvm-nm inclusion)
 - #94260 (Fix rustdoc infinite redirection generation)
 - #94263 (Typo fix: Close inline-code backtick)
 - #94264 (Fix typo.)
 - #94271 (Miri: extend comments on downcast operation)
 - #94280 (Rename `region_should_not_be_omitted` to `should_print_region`)
 - #94285 (Sync rustc_codegen_cranelift)

Failed merges:

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

Rust previously encoded the `char` type as DW_ATE_unsigned_char. The more
appropriate encoding is DW_ATE_UTF.

Clang uses this same debug encoding for char32_t.

This fixes the display of `char` types in Windows debuggers as well as LLDB.

Sync rustc_codegen_cranelift

r? `@ghost`

`@rustbot` label +A-codegen +A-cranelift +T-compiler

Rename `region_should_not_be_omitted` to `should_print_region`

to avoid double negation

Miri: extend comments on downcast operation

r? `@oli-obk`

Fix typo.

Yeah just a typo (probably some breaking changes in here be careful) :)

Typo fix: Close inline-code backtick

A drop in the ocean.

Fix rustdoc infinite redirection generation

Someone came to me about a funny bug they had when clicking on any link on [this page](https://world.pages.gitlab.gnome.org/Rust/libadwaita-rs/stable/latest/docs/libadwaita/builders/index.html): it ended one page redirecting to itself indefinitely.

I was able to make a minimum reproducible case to trigger this bug which I now use as a test.

r? ``@notriddle``

Bump download-ci-llvm-stamp for llvm-nm inclusion

We started using it in https://github.com/rust-lang/rust/pull/94023.

Use 2021 edition in ./x.py fmt

Suggest calling .display() on `PathBuf` too

Fixes #94210

fix names in feature(...) suggestion

rustdoc-json: Better Header Type

- Make ABI an enum, instead of being stringly typed
- Replace Qualifier HashSet with 3 bools
- Merge ABI field into header, as they always occor together

r? ``@CraftSpider``

``@rustbot`` modify labels: +A-rustdoc-json +T-rustdoc