Rollup of 11 pull requests

Successful merges:

 - #152880 (Tweak incorrect assoc item note)
 - #153526 (Fix LegacyKeyValueFormat report from docker build: i686)
 - #153613 (interpreter error reporting: remove arguments that are always the same)
 - #154029 (Replace `truncate(0)` with `clear()`)
 - #154125 (Inline and remove `DepGraphData::try_mark_parent_green`.)
 - #154185 (Prevent no_threads RwLock's write() impl from setting mode to -1 when it is locked for reading)
 - #154394 (Normalize rustc path prefix when testing `-Z track-diagnostics`)
 - #154450 (Use the normal arg-parsing machinery for `-Zassert-incr-state`)
 - #154475 (Emit a pre-expansion feature gate warning for `box`'ed struct field patterns)
 - #154500 (EnumSizeOpt: use Allocation::write_scalar instead of manual endianess logic)
 - #154502 (interpret: ensure that untupled arguments are actually tuples)

Rollup merge of #154475 - fmease:soft-gate-box-struct-field-pat, r=Kivooeo

Emit a pre-expansion feature gate warning for `box`'ed struct field patterns

While the following code triggers a feature gate *warning*:

```rs
fn f() {
    #[cfg(false)]
    let box x; //~ WARN box pattern syntax is experimental
}
```

the code below does not (on stable & main):

```rs
fn f() {
    #[cfg(false)]
    let Struct { box x };
}
```

This is an oversight as both are part of the unstable feature `box_patterns` (that isn't properly gated pre expansion for historical reasons). Of course, both forms lead to a feature gate error *post expansion*.

This is a bug fix and doesn't need any input from T-compiler or T-lang. For context, emitting warnings in these cases is legitimized by [MCP 535](https://github.com/rust-lang/compiler-team/issues/535)[^1].

Part of #154045.

[^1]: In case you're wondering why the MCP talks about a *lint* even though the feature gate warnings as seen today don't reference any lint by name, read #154045 (comment).

Emit pre-expansion feature gate warnings for negative impls and specialization

Follow up to rust-lang#154475; part of rust-lang#154045.

This shouldn't need any extra input from T-compiler or T-lang since it's legitimized by [MCP 535](rust-lang/compiler-team#535).

However, I have a feeling that negative impls & specialization behind "`#[cfg(feature = "nightly")]`" are more prevalent in the ecosystem compared to e.g., auto traits & box patterns, so these new warnings will probably hit a bunch of users. In any case, it's only a warning for now not an error so e.g., running crater "in deny mode" or nominating for a T-lang meeting discussion would be disproportionate (esp. since T-lang [has confirmed in the past](rust-lang#116393 (comment)) that this is a T-compiler matter).

Emit pre-expansion feature gate warnings for negative impls and specialization

Follow up to rust-lang#154475; part of rust-lang#154045.

This shouldn't need any extra input from T-compiler or T-lang since it's legitimized by [MCP 535](rust-lang/compiler-team#535).

However, I have a feeling that negative impls & specialization behind "`#[cfg(feature = "nightly")]`" are more prevalent in the ecosystem compared to e.g., auto traits & box patterns, so these new warnings will probably hit a bunch of users. In any case, it's only a warning for now not an error so e.g., running crater "in deny mode" or nominating for a T-lang meeting discussion would be disproportionate (esp. since T-lang [has confirmed in the past](rust-lang#116393 (comment)) that this is a T-compiler matter).

Emit pre-expansion feature gate warnings for negative impls and specialization

Follow up to rust-lang#154475; part of rust-lang#154045.

This shouldn't need any extra input from T-compiler or T-lang since it's legitimized by [MCP 535](rust-lang/compiler-team#535).

However, I have a feeling that negative impls & specialization behind "`#[cfg(feature = "nightly")]`" are more prevalent in the ecosystem compared to e.g., auto traits & box patterns, so these new warnings will probably hit a bunch of users. In any case, it's only a warning for now not an error so e.g., running crater "in deny mode" or nominating for a T-lang meeting discussion would be disproportionate (esp. since T-lang [has confirmed in the past](rust-lang#116393 (comment)) that this is a T-compiler matter).

Emit pre-expansion feature gate warnings for negative impls and specialization

Follow up to rust-lang#154475; part of rust-lang#154045.

This shouldn't need any extra input from T-compiler or T-lang since it's legitimized by [MCP 535](rust-lang/compiler-team#535).

However, I have a feeling that negative impls & specialization behind "`#[cfg(feature = "nightly")]`" are more prevalent in the ecosystem compared to e.g., auto traits & box patterns, so these new warnings will probably hit a bunch of users. In any case, it's only a warning for now not an error so e.g., running crater "in deny mode" or nominating for a T-lang meeting discussion would be disproportionate (esp. since T-lang [has confirmed in the past](rust-lang#116393 (comment)) that this is a T-compiler matter).

Emit pre-expansion feature gate warnings for negative impls and specialization

Follow up to rust-lang#154475; part of rust-lang#154045.

This shouldn't need any extra input from T-compiler or T-lang since it's legitimized by [MCP 535](rust-lang/compiler-team#535).

However, I have a feeling that negative impls & specialization behind "`#[cfg(feature = "nightly")]`" are more prevalent in the ecosystem compared to e.g., auto traits & box patterns, so these new warnings will probably hit a bunch of users. In any case, it's only a warning for now not an error so e.g., running crater "in deny mode" or nominating for a T-lang meeting discussion would be disproportionate (esp. since T-lang [has confirmed in the past](rust-lang#116393 (comment)) that this is a T-compiler matter).

Rollup merge of #154527 - fmease:more-soft-gates, r=nnethercote

Emit pre-expansion feature gate warnings for negative impls and specialization

Follow up to #154475; part of #154045.

This shouldn't need any extra input from T-compiler or T-lang since it's legitimized by [MCP 535](rust-lang/compiler-team#535).

However, I have a feeling that negative impls & specialization behind "`#[cfg(feature = "nightly")]`" are more prevalent in the ecosystem compared to e.g., auto traits & box patterns, so these new warnings will probably hit a bunch of users. In any case, it's only a warning for now not an error so e.g., running crater "in deny mode" or nominating for a T-lang meeting discussion would be disproportionate (esp. since T-lang [has confirmed in the past](#116393 (comment)) that this is a T-compiler matter).

Emit pre-expansion feature gate warnings for negative impls and specialization

Follow up to rust-lang/rust#154475; part of rust-lang/rust#154045.

This shouldn't need any extra input from T-compiler or T-lang since it's legitimized by [MCP 535](rust-lang/compiler-team#535).

However, I have a feeling that negative impls & specialization behind "`#[cfg(feature = "nightly")]`" are more prevalent in the ecosystem compared to e.g., auto traits & box patterns, so these new warnings will probably hit a bunch of users. In any case, it's only a warning for now not an error so e.g., running crater "in deny mode" or nominating for a T-lang meeting discussion would be disproportionate (esp. since T-lang [has confirmed in the past](rust-lang/rust#116393 (comment)) that this is a T-compiler matter).