MIR required_consts, mentioned_items: ensure we do not forget to fill these lists
Bodies initially get created with empty required_consts and mentioned_items, but at some point those should be filled. Make sure we notice when that is forgotten.
Remove more `#[macro_use] extern crate tracing`
Because explicit importing of macros via use items is nicer (more standard and readable) than implicit importing via `#[macro_use]`. Continuing the work from #124511 and #124914.
r? `@jackh726`
clean up `Sized` checking
This PR cleans up `sized_constraint` and related functions to make them simpler and faster. This should not make more or less code compile, but it can change error output in some rare cases.
## enums and unions are `Sized`, even if they are not WF
The previous code has some special handling for enums, which made them sized if and only if the last field of each variant is sized. For example given this definition (which is not WF)
```rust
enum E<T1: ?Sized, T2: ?Sized, U1: ?Sized, U2: ?Sized> {
A(T1, T2),
B(U1, U2),
}
```
the enum was sized if and only if `T2` and `U2` are sized, while `T1` and `T2` were ignored for `Sized` checking. After this PR this enum will always be sized.
Unsized enums are not a thing in Rust and removing this special case allows us to return an `Option<Ty>` from `sized_constraint`, rather than a `List<Ty>`.
Similarly, the old code made an union defined like this
```rust
union Union<T: ?Sized, U: ?Sized> {
head: T,
tail: U,
}
```
sized if and only if `U` is sized, completely ignoring `T`. This just makes no sense at all and now this union is always sized.
## apply the "perf hack" to all (non-error) types, instead of just type parameters
This "perf hack" skips evaluating `sized_constraint(adt): Sized` if `sized_constraint(adt): Sized` exactly matches a predicate defined on `adt`, for example:
```rust
// `Foo<T>: Sized` iff `T: Sized`, but we know `T: Sized` from a predicate of `Foo`
struct Foo<T /*: Sized */>(T);
```
Previously this was only applied to type parameters and now it is applied to every type. This means that for example this type is now always sized:
```rust
// Note that this definition is WF, but the type `S<T>` not WF in the global/empty ParamEnv
struct S<T>([T]) where [T]: Sized;
```
I don't anticipate this to affect compile time of any real-world program, but it makes the code a bit nicer and it also makes error messages a bit more consistent if someone does write such a cursed type.
## tuples are sized if the last type is sized
The old solver already has this behavior and this PR also implements it for the new solver and `is_trivially_sized`. This makes it so that tuples work more like a struct defined like this:
```rust
struct TupleN<T1, T2, /* ... */ Tn: ?Sized>(T1, T2, /* ... */ Tn);
```
This might improve the compile time of programs with large tuples a little, but is mostly also a consistency fix.
## `is_trivially_sized` for more types
This function is used post-typeck code (borrowck, const eval, codegen) to skip evaluating `T: Sized` in some cases. It will now return `true` in more cases, most notably `UnsafeCell<T>` and `ManuallyDrop<T>` where `T.is_trivially_sized`.
I'm anticipating that this change will improve compile time for some real world programs.
First, introduce a typedef `DiagnosticArgMap`.
Second, make the `args` field public, and remove the `args` getter and
`replace_args` setter. These were necessary previously because the getter
had a `#[allow(rustc::potential_query_instability)]` attribute, but that
was removed in #120931 when the args were changed from `FxHashMap` to
`FxIndexMap`. (All the other `Diagnostic` fields are public.)
Instead we re-use the static's alloc id within the interpreter for its initializer to refer to the `Allocation` that only exists within the interpreter.
It's only has a single remaining purpose: to ensure that a diagnostic is
printed when `trimmed_def_paths` is used. It's an annoying mechanism:
weak, with odd semantics, badly named, and gets in the way of other
changes.
This commit replaces it with a simpler `must_produce_diag` mechanism,
getting rid of a diagnostic `Level` along the way.
Dejargonize `subst`
In favor of #110793, replace almost every occurence of `subst` and `substitution` from rustc codes, but they still remains in subtrees under `src/tools/` like clippy and test codes (I'd like to replace them after this)
Because it also has a `DiagnosticBuilder` arg, which contains a `dcx`
reference.
Also rename some `builder` variables as `diag`, because that's the usual
name.
