Use `MPlaceTy` instead of `PlaceTy` in `FnArg` and ignore (copy) locals in an
earlier step ("Locals that don't have their address taken are as protected as
they can ever be").

This seems to be crucial for tail call support (as they can't refer to caller's
locals which are killed when replacing the stack frame).

…rors

… fail to align

…s for some MSVC targets

…cuviper

align_offset, align_to: no longer allow implementations to spuriously fail to align

For a long time, we have allowed `align_offset` to fail to compute a properly aligned offset, and `align_to` to return a smaller-than-maximal "middle slice". This was done to cover the implementation of `align_offset` in const-eval and Miri. See rust-lang#62420 for more background. For about the same amount of time, this has caused confusion and surprise, where people didn't realize they have to write their code to be defensive against `align_offset` failures.

Another way to put this is: the specification is effectively non-deterministic, and non-determinism is hard to test for -- in particular if the implementation everyone uses to test always produces the same reliable result, and nobody expects it to be non-deterministic to begin with.

With rust-lang#117840, Miri has stopped making use of this liberty in the spec; it now always behaves like rustc. That only leaves const-eval as potential motivation for this behavior. I do not think this is sufficient motivation. Currently, none of the relevant functions are stably const: `align_offset` is unstably const, `align_to` is not const at all. I propose that if we ever want to make these const-stable, we just accept the fact that they can behave differently at compile-time vs at run-time. This is not the end of the world, and it seems to be much less surprising to programmers than unexpected non-determinism. (Related: rust-lang/rfcs#3352.)

`@thomcc` has repeatedly made it clear that they strongly dislike the non-determinism in align_offset, so I expect they will support this. `@oli-obk,` what do you think? Also, whom else should we involve? The primary team responsible is clearly libs-api, so I will nominate this for them. However, allowing const-evaluated code to behave different from run-time code is t-lang territory. The thing is, this is not stabilizing anything t-lang-worthy immediately, but it still does make a decision we will be bound to: if we accept this change, then
- either `align_offset`/`align_to` can never be called in const fn,
- or we allow compile-time behavior to differ from run-time behavior.

So I will nominate for t-lang as well, with the question being: are you okay with accepting either of these outcomes (without committing to which one, just accepting that it has to be one of them)? This closes the door to "have `align_offset` and `align_to` at compile-time and also always have compile-time behavior match run-time behavior".

Closes rust-lang#62420

Tweak the way we protect in-place function arguments in interpreters

Use `MPlaceTy` instead of `PlaceTy` in `FnArg` and ignore (copy) locals in an earlier step ("Locals that don't have their address taken are as protected as they can ever be").

This seems to be crucial for tail call support (as they can't refer to caller's locals which are killed when replacing the stack frame).

r? `@RalfJung`
cc `@oli-obk`
see rust-lang#121273 (comment)

…oli-obk

Better comment for implicit captures in RPITIT

Improve the error message for implicit captures. Also always set E0657.

r? oli-obk

Add the new description field to Target::to_json, and add descriptions for some MSVC targets

The original PR to add a `description` field to `Target` (<rust-lang#121905>) didn't add the field to `Target::to_json`, which meant that the `check_consistency` testwould fail if you tried to set a description as it wouldn't survive round-tripping via JSON: https://github.com/rust-lang/rust/actions/runs/8180997936/job/22370052535#step:27:4967

This change adds the field to `Target::to_json`, and sets some descriptions to verify that it works correctly.

…gjubilee

Fix misaligned loads when loading UEFI arg pointers

Currently, the two UEFI argument pointers are stored in an `alloca` of alignment 1, a pointer to which is then passed as `argv`. However, [the library code](https://github.com/rust-lang/rust/blob/9c3ad802d9b9633d60d3a74668eb1be819212d34/library/std/src/sys/pal/uefi/mod.rs#L60-L61) treats `argv` as a pointer to an array of pointers and dereferences it as such, meaning that it presumes the `alloca` is aligned to at least the alignment of a pointer. This PR fixes this mismatch by aligning the `alloca` to the alignment of a pointer.

This PR also changed the `gep` to use the new `inbounds_ptradd` method.

… r=lcnr

Add some new solver tests

Fixes rust-lang#119607
Fixes rust-lang#119608

r? lcnr

…, r=fmease

Don't ICE if we collect no RPITITs unless there are no unification errors

Move an assertion in `collect_return_position_impl_trait_in_trait_tys` to after the `ObligationCtxt::eq` calls, so that we only assert and ICE if we have unification errors.

Fixes rust-lang#121468

inspect formatter: add braces

This makes it easier to hide subtrees when looking through proof trees. Looking at the proof tree for `usize: Clone`:

nightly:
```
ROOT GOAL: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } }
    GOAL: Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } }, anchor: Bind(DefId(0:5 ~ main[8e4b]::main)), predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [] }
    REVISION 0
        INSTANTIATED: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } }, anchor: Bind(DefId(0:5 ~ main[8e4b]::main)), predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }
        ROOT RESULT: Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] })
            CANDIDATE Impl(DefId(2:30665 ~ core[a9f5]::clone::impls::{impl#5})): Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] })
                TRY_EVALUATE_ADDED_GOALS: Ok(Yes)
                ITERATION 0
            CANDIDATE constituent tys: Err(NoSolution)
            NORMALIZING SELF TY FOR ASSEMBLY:
            NORMALIZING SELF TY FOR ASSEMBLY:
    RESULT: Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] })
```

with this PR:
```
ROOT GOAL: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } } {
    GOAL: Canonical { value: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } }, anchor: Bind(DefId(0:5 ~ main[4f74]::main)), predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }, max_universe: U0, variables: [] }
    REVISION 0: {
        INSTANTIATED: QueryInput { goal: Goal { predicate: Binder { value: TraitPredicate(<usize as std::clone::Clone>, polarity:Positive), bound_vars: [] }, param_env: ParamEnv { caller_bounds: [], reveal: UserFacing } }, anchor: Bind(DefId(0:5 ~ main[4f74]::main)), predefined_opaques_in_body: PredefinedOpaques(PredefinedOpaquesData { opaque_types: [] }) }
        ROOT RESULT: Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] }) {
            CANDIDATE Impl(DefId(2:30468 ~ core[d1d7]::clone::impls::{impl#5})): Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] }) {
                TRY_EVALUATE_ADDED_GOALS: Ok(Yes)
                ITERATION 0 {}
            }
            CANDIDATE constituent tys: Err(NoSolution) {}
            NORMALIZING SELF TY FOR ASSEMBLY: {}
            NORMALIZING SELF TY FOR ASSEMBLY: {}
        }
    }
    RESULT: Ok(Canonical { value: Response { certainty: Yes, var_values: CanonicalVarValues { var_values: [] }, external_constraints: ExternalConstraints(ExternalConstraintsData { region_constraints: QueryRegionConstraints { outlives: [], member_constraints: [] }, opaque_types: [] }) }, max_universe: U0, variables: [] })
}
```

r? `@BoxyUwU`

Remove handling for previously dropped LLVM version

LLVM 14 support was dropped in rust-lang#114148, so this LLVM version check is no longer required.