[5/n] rustc: record the target type of every adjustment.
_This is part of a series ([prev](https://github.com/rust-lang/rust/pull/37404) | [next](https://github.com/rust-lang/rust/pull/37412)) of patches designed to rework rustc into an out-of-order on-demand pipeline model for both better feature support (e.g. [MIR-based](https://github.com/solson/miri) early constant evaluation) and incremental execution of compiler passes (e.g. type-checking), with beneficial consequences to IDE support as well.
If any motivation is unclear, please ask for additional PR description clarifications or code comments._
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The first commit rearranges `tcx.tables` so that all users go through `tcx.tables()`. This in preparation for per-body `Tables` where they will be requested for a specific `DefId`. Included to minimize churn.
The rest of the changes focus on adjustments, there are some renamings, but the main addition is the target type, always available in all cases (as opposed to just for unsizing where it was previously needed).
Possibly the most significant effect of this change is that figuring out the final type of an expression is now _always_ just one successful `HashMap` lookup (either the adjustment or, if that doesn't exist, the node type).
Diagnostics for struct path resolution errors in resolve and typeck are unified.
Self type is treated as a type alias in few places (not reachable yet).
Unsafe cell is seen in constants even through type aliases.
All checks for struct paths in typeck work on type level.
incr. comp.: Take spans into account for ICH
This PR makes the ICH (incr. comp. hash) take spans into account when debuginfo is enabled.
A side-effect of this is that the SVH (which is based on the ICHs of all items in the crate) becomes sensitive to the tiniest change in a code base if debuginfo is enabled. Since we are not trying to model ABI compatibility via the SVH anymore (this is done via the crate disambiguator now), this should be not be a problem.
Fixes#33888.
Fixes#32753.
Turn the RFC1592 warnings into hard errors
The warnings have already reached stable, and I want to improve the trait error reporting code.
Turning warnings into errors, this is obviously a [breaking-change].
r? @nikomatsakis
cc @rust-lang/compiler
Rename _ to {integer} and {float} for unknown numeric types
This PR renames _ to {integer} or {float} for unknown numeric types, to help people parse error messages that have numeric types that haven't been nailed down.
Example:
```rust
fn main() {
let x: String = 4;
}
```
Before:
```
error[E0308]: mismatched types
--> quicktest.rs:2:21
|
2 | let x: String = 4;
| ^ expected struct `std::string::String`, found integral variable
|
= note: expected type `std::string::String`
= note: found type `_`
error: aborting due to previous error
```
after:
```
error[E0308]: mismatched types
--> quicktest.rs:2:21
|
2 | let x: String = 4;
| ^ expected struct `std::string::String`, found integral variable
|
= note: expected type `std::string::String`
= note: found type `{integer}`
error: aborting due to previous error
```
```
This indicates whether this `BoundRegion` will change from late to early
bound when issue 32330 is fixed. It also indicates the function on
which the lifetime is declared.
