This updates the tests to be consistent with argv in modern C/C++ applications.

As derived from extensive testing of `argv` in a C/C++ application.

Co-Authored-By: Jane Lusby <jlusby42@gmail.com>

Co-authored-by: kennytm <kennytm@gmail.com>

Issue Details:
In some cases it is necessary to generate an "allocator shim" to forward various Rust allocation functions (e.g., `__rust_alloc`) to an underlying function (e.g., `malloc`). However, since this allocator shim is a manually created LLVM module it is not processed via the normal module processing code and so no debug info is generated for it (if debugging info is enabled).

Fix Details:
* Modify the `debuginfo` code to allow creating debug info for a module without a `CodegenCx` (since it is difficult, and expensive, to create one just to emit some debug info).
* After creating the allocator shim add in basic debug info.

Fixes rust-lang#88519

Lint missing Abi in ast validation instead of lowering.

…-ou-se

Update Windows Argument Parsing

Fixes rust-lang#44650

The Windows command line is passed to applications [as a single string](https://docs.microsoft.com/en-us/archive/blogs/larryosterman/the-windows-command-line-is-just-a-string) which the application then parses to get a list of arguments. The standard rules (as used by C/C++) for parsing the command line have slightly changed over the years, most recently in 2008 which added new escaping rules.

This PR implements the new rules as [described on MSDN](https://docs.microsoft.com/en-us/cpp/cpp/main-function-command-line-args?view=msvc-160#parsing-c-command-line-arguments) and [further detailed here](https://daviddeley.com/autohotkey/parameters/parameters.htm#WIN). It has been tested against the behaviour of C++ by calling a C++ program that outputs its raw command line and the contents of `argv`. See [my repo](https://github.com/ChrisDenton/winarg/tree/std) if anyone wants to reproduce my work.

For an overview of how this PR changes argument parsing behavior and why we feel it is warranted see rust-lang#87580 (comment).

For some examples see: rust-lang#87580 (comment)

…lementors-display, r=camelid,Manishearth

Display associated types of implementors

Fixes rust-lang#86631.

Contrary to before, it doesn't display methods. I also had to "resurrect" the `auto-hide-trait-implementations` setting. :3

Only question at this point: should I move the `render_impl` boolean arguments into one struct? We're starting to have quite a lot of them...

cc `@cynecx`
r? `@camelid`

…=kennytm

Use `unwrap_unchecked` where possible

Shrink Session a bit

Remove a couple of unnecessary fields from `Session` and remove a `Lock<T>` for a field that is never mutated anyway.

Remove single use variables

…ck-fragment, r=estebank

Improve closure dummy capture suggestion in macros.

Fixes some cases of rust-lang#88440

Fixes https://crater-reports.s3.amazonaws.com/pr-87190-3/try%23a7a572ce3edd6d476191fbfe92c9c1986e009b34/reg/rcodec-1.0.1/log.txt

…necessary, r=davidtwco

fix(rustc_lint): better detect when parens are necessary

Fixes rust-lang#88519

…o, r=estebank

Include debug info for the allocator shim

Issue Details:
In some cases it is necessary to generate an "allocator shim" to forward various Rust allocation functions (e.g., `__rust_alloc`) to an underlying function (e.g., `malloc`). However, since this allocator shim is a manually created LLVM module it is not processed via the normal module processing code and so no debug info is generated for it (if debugging info is enabled).

Fix Details:
* Modify the `debuginfo` code to allow creating debug info for a module without a `CodegenCx` (since it is difficult, and expensive, to create one just to emit some debug info).
* After creating the allocator shim add in basic debug info.

`fmt::Formatter::pad`: don't call chars().count() more than one time

First commit merges two branches of match to call chars().count() only once: that should be faster if this method hits place of 3rd (previous) branch, plus quarter shorter.
Second commit fixes some clippy lints while i'm here (should it be separate PR?).

Add regression test for issue 83190

Reduced from `bioyino-metric` by `@hellow554` and myself.

Closes rust-lang#83190.

r? `@spastorino`