This commit fixes debug printing of function pointers on AVR. AVR does
not support `addrspacecast` instructions, and so this patch modifies
libcore so that a `ptrtoint` IR instruction is used and the address
space cast is avoided.

…ing convention

Also fix the order of the feature gate to fix the tidy errors.

Patch generated with `./x.py test --stage 1 src/test/ui/feature-gates --bless`.

Adding a new ABI changes the hashes of all previous ABIs.

Fix suggested by @shepmaster in
rust-lang#69478 (comment).

It is not possible to compile libstd for AVR anyway.

… ABI

This patch brings the AVR calling convention argument classification
logic in line with AVR Clang's behaviour.

AVR-Clang currently uses the `clang::DefaultABIInfo` ABI implementation.
This calling convention promotes all aggregates to indirect, no matter their
size.

It is also unnecessary to perform any integer width extension for AVR as
the minimum argument size matches the minimum describable size of
abi::Primitive::Int - 8 bits.

At some point in the future, an AVR-GCC compatible argument
classification implementation should be adopted in both Clang and Rust.

Normally, we debug-print `Spans` using the `SourceMap` retrieved from
the global `TyCtxt`. However, we fall back to printing out the `Span`'s
raw fields (instead of a file and line number) when we try to print a
`Span` before a `TyCtxt` is available. This makes debugging early phases
of the compile, such as parsing, much more difficult.

This commit stores a `SourceMap` in `rustc_span::GlOBALS` as a fallback.
When a `TyCtxt` is not available, we try to retrieve one from `GLOBALS`
- only if this is not available do we fall back to the raw field output.

I'm not sure how to write a test for this - however, this can be
verified locally by setting `RUSTC_LOG="rustc_parse=debug"`, and
verifying that the output contains filenames and line numbers.

…nas-schievink

Enable AVR as a Tier 3 target upstream

Tracking issue: rust-lang#44052.

Things intentionally left out of the initial upstream:

* The `target_cpu` flag

I have made the cleanup suggestions by @jplatte and @jplatte in avr-rust@043550d.

Anybody feel free to give the branch a test and see how it fares, or make suggestions on the code patch itself.

…r=petrochenkov

Make `SourceMap` available for early debug-printing of `Span`s

Normally, we debug-print `Spans` using the `SourceMap` retrieved from
the global `TyCtxt`. However, we fall back to printing out the `Span`'s
raw fields (instead of a file and line number) when we try to print a
`Span` before a `TyCtxt` is available. This makes debugging early phases
of the compile, such as parsing, much more difficult.

This commit stores a `SourceMap` in `rustc_span::GlOBALS` as a fallback.
When a `TyCtxt` is not available, we try to retrieve one from `GLOBALS`
- only if this is not available do we fall back to the raw field output.

I'm not sure how to write a test for this - however, this can be
verified locally by setting `RUSTC_LOG="rustc_parse=debug"`, and
verifying that the output contains filenames and line numbers.

…atthewjasper

On recursive ADT, provide indirection structured suggestion

Return early to avoid ICE

Fixes rust-lang#72766

bump Miri, update for cargo-miri being a separate project

r? @oli-obk

Fixes rust-lang#72801

…nas-schievink

validate basic sanity for TerminatorKind

r? @jonas-schievink

This mainly checks that all `BasicBlock` actually exist. On top of that, it checks that `Call` actually calls something of `FnPtr`/`FnDef` type, and `Assert` has to work on a `bool`. Also `SwitchInt` cannot have an empty target list.