… style

For some reason the absolute paths were formatted differently on the
armhf-gnu target.

    thread '<unnamed>' panicked at 'assertion failed: `(left == right)`
      left: `"Backtrace [\n    { fn: \"__rust_maybe_catch_panic\" },\n    { fn: \"std::rt::lang_start_internal\", file: \"./rust/rt.rs\", line: 300 },\n    { fn: \"std::rt::lang_start\", file: \"./rust/rt.rs\", line: 400 },\n]"`,
     right: `"Backtrace [\n    { fn: \"__rust_maybe_catch_panic\" },\n    { fn: \"std::rt::lang_start_internal\", file: \"/rust/rt.rs\", line: 300 },\n    { fn: \"std::rt::lang_start\", file: \"/rust/rt.rs\", line: 400 },\n]"`', src/libstd/backtrace.rs:486:5

…d a long lost assertion

This reverts part of commit 9712fa4.

Co-Authored-By: Ralf Jung <post@ralfj.de>

Backtrace Debug tweaks

- Change Debug representation of disabled and unsupported backtraces to use \<placeholder\> style, same as what we do for debug printing locked mutexes and mutably borrowed refcells;

    ```diff
    - Error { msg: "...", backtrace: disabled backtrace }
    + Error { msg: "...", backtrace: <disabled> }
    ```

- Remove quotes around unresolved symbol names;

    ```diff
    - Backtrace [{ fn: "<unknown>" }]
    + Backtrace [{ fn: <unknown> }]
    ```

- Add quotes around file paths;

    ```diff
    - Backtrace [{ fn: "krate::main", file: /path/to/main.rs, line: 10 }]
    + Backtrace [{ fn: "krate::main", file: "/path/to/main.rs", line: 10 }]
    ```

- Add test.

…sper

Change "method" to "associated function"

r? @matthewjasper

cc @Centril @eddyb rust-lang#67742

I'm opening this mostly as a test to see what the diagnostic changes would be. It seems that this makes them somewhat more verbose, and I'm not sure it's worth it...

The relevant changes are the last two commits (it is rebased on top of rust-lang#67742)

ast: `Mac`/`Macro` -> `MacCall`

It's now obvious that these refer to macro calls rather than to macro definitions.

It's also a single name instead of two different names in different places.

`rustc_expand` usually calls macro calls in a wide sense (including attributes and derives) "macro invocations", but structures and variants renamed in this PR are only relevant to fn-like macros, so it's simpler and clearer to just call them calls.

cc rust-lang#63586 (comment)
r? @eddyb

update backtrace crate

In particular this release includes rust-lang/backtrace-rs#297 and rust-lang/backtrace-rs#300.

More Method -> AssocFn renaming

r? @Centril @eddyb

cc rust-lang#60163

Blocked on rust-lang#69674

…lfJung

Compute the correct layout for variants of uninhabited enums

r? @eddyb
cc @RalfJung

fixes rust-lang#69191
cc rust-lang#69763

…lacrum

Regenerate tables for Unicode 13.0.0

Add self to .mailmap

The variants are only used for [rust-lang/rust-clippy](https://github.com/rust-lang/rust-clippy), but it seems like <https://thanks.rust-lang.org/> only uses this `.mailmap`.