Error messages are supposed to start with lowercase letters, but a lot
of `io::const_error` messages did not. This fixes them to start with a
lowercase letter.
I did consider adding a const check for this to the macro, but some of
them start with proper nouns that make sense to uppercase them.

See https://doc.rust-lang.org/1.85.0/std/error/trait.Error.html

Per discussion in rust-lang#137799 we don't really need this readonly attribute,
so let's just drop it so the test passes on LLVM 21.

Fixes rust-lang#137799.

Make suggestions verbose.

When encountering `method(type)` bound, suggest `method(..)` instead of `method()`.

```
error: argument types not allowed with return type notation
  --> $DIR/bad-inputs-and-output.rs:9:23
   |
LL | fn foo<T: Trait<method(i32): Send>>() {}
   |                       ^^^^^
   |
help: remove the input types
   |
LL - fn foo<T: Trait<method(i32): Send>>() {}
LL + fn foo<T: Trait<method(..): Send>>() {}
   |
```

When encountering both return type and arg list that isn't `..`, suggest replacing both.

```
error: return type not allowed with return type notation
  --> $DIR/bad-inputs-and-output.rs:12:25
   |
LL | fn bar<T: Trait<method() -> (): Send>>() {}
   |                         ^^^^^^
   |
help: use the right argument notation and remove the return type
   |
LL - fn bar<T: Trait<method() -> (): Send>>() {}
LL + fn bar<T: Trait<method(..): Send>>() {}
   |
```

When encountering a return type, suggest removing it including the leading whitespace.

```
error: return type not allowed with return type notation
  --> $DIR/bad-inputs-and-output.rs:24:45
   |
LL | fn bay_path<T: Trait>() where T::method(..) -> (): Send {}
   |                                             ^^^^^
   |
help: remove the return type
   |
LL - fn bay_path<T: Trait>() where T::method(..) -> (): Send {}
LL + fn bay_path<T: Trait>() where T::method(..): Send {}
   |
```

Fixes rust-lang#137739. A reproducer of the issue is present there. I believe the
root cause was introducing the avr-none target (which has no CPU by
default) and trying to get the ISA revision from there. This commit
uses the `target-cpu` option instead, which is already required to be
present for the target.

Co-authored-by: tones111 <[email protected]>

these all also accept integer vectors as arguments

this is because they may be widened, and that only works when sign extension is used: zero extension would produce invalid results

Per the [Zulip thread](https://rust-lang.zulipchat.com/#narrow/channel/146212-t-compiler.2Fconst-eval/topic/rustbot.20pings).

Move documentation to query definitions, and add docs to
`explicit_implied_const_bounds`.

… r=workingjubilee

rename BackendRepr::Vector → SimdVector

For many Rustaceans, "vector" does not imply "SIMD", so let's be more clear in this type that is used pervasively in the compiler.

r? `@workingjubilee`

…ult, r=notriddle

Fully qualify `Result` in generated doctest code

As discussed in https://lore.kernel.org/rust-for-linux/[email protected]/T/#u, it would require less code for RfL to be able to reach the same result (pun unintended).

cc ``@ojeda``

r? ``@notriddle``

Use correct error message casing for `io::const_error`s

Error messages are supposed to start with lowercase letters, but a lot of `io::const_error` messages did not. This fixes them to start with a lowercase letter.
I did consider adding a const check for this to the macro, but some of them start with proper nouns that make sense to uppercase them.

See https://doc.rust-lang.org/1.85.0/std/error/trait.Error.html

…=jieyouxu

tests: adapt for LLVM 21 changes

Per discussion in rust-lang#137799 we don't really need this readonly attribute, so let's just drop it so the test passes on LLVM 21.

Fixes rust-lang#137799.

…ompiler-errors

Update query normalizer docs to not position it as the greatest pioneer in the space of normalization

I don't think its true that we intend to replace all normalization with the query normalizer- its more likely that once the new solver is stable we can replace the query normalizer with normal normalization calls as the new solver caches much more than the old solver

r? ``@compiler-errors``

Tweak invalid RTN errors

Make suggestions verbose.

When encountering `method(type)` bound, suggest `method(..)` instead of `method()`.

```
error: argument types not allowed with return type notation
  --> $DIR/bad-inputs-and-output.rs:9:23
   |
LL | fn foo<T: Trait<method(i32): Send>>() {}
   |                       ^^^^^
   |
help: remove the input types
   |
LL - fn foo<T: Trait<method(i32): Send>>() {}
LL + fn foo<T: Trait<method(..): Send>>() {}
   |
```

When encountering both return type and arg list that isn't `..`, suggest replacing both.

```
error: return type not allowed with return type notation
  --> $DIR/bad-inputs-and-output.rs:12:25
   |
LL | fn bar<T: Trait<method() -> (): Send>>() {}
   |                         ^^^^^^
   |
help: use the right argument notation and remove the return type
   |
LL - fn bar<T: Trait<method() -> (): Send>>() {}
LL + fn bar<T: Trait<method(..): Send>>() {}
   |
```

When encountering a return type, suggest removing it including the leading whitespace.

```
error: return type not allowed with return type notation
  --> $DIR/bad-inputs-and-output.rs:24:45
   |
LL | fn bay_path<T: Trait>() where T::method(..) -> (): Send {}
   |                                             ^^^^^
   |
help: remove the return type
   |
LL - fn bay_path<T: Trait>() where T::method(..) -> (): Send {}
LL + fn bay_path<T: Trait>() where T::method(..): Send {}
   |
```

r? ``@compiler-errors``

…s, r=workingjubilee

Fix inaccurate `std::intrinsics::simd` documentation

This addresses two issues:

- the docs on comparison operators (`simd_gt` etc.) said they only work for floating-point vectors, but they work for integer vectors too.
- the docs on various functions that use a mask did not document that the mask must be a signed integer vector. Unsigned integer vectors would cause invalid behavior when the mask vector is widened (unsigned integers would use zero extension, producing incorrect results).

r? ``@workingjubilee``

…r=workingjubilee

Fix link failure on AVR (incompatible ISA error)

Fixes rust-lang#137739. A reproducer of the issue is present there. I believe the root cause was introducing the avr-none target (which has no CPU by default) while also trying to get the ISA revision from the target spec. This commit uses the `target-cpu` option instead, which is already required to be present for the target.

r? compiler
cc ``@Patryk27``

…y, r=compiler-errors

Update `const_conditions` and `explicit_implied_const_bounds` docs

Move documentation to query definitions, and add docs to `explicit_implied_const_bounds`.

r? project-const-traits

…s, r=oli-obk

triagebot: only ping me for constck

Per the [Zulip thread](https://rust-lang.zulipchat.com/#narrow/channel/146212-t-compiler.2Fconst-eval/topic/rustbot.20pings).

cc `@rust-lang/wg-const-eval.`