Done previously as a part of
rust-lang#58748

Ensure the core::ffi::VaList structure passes the improper_ctypes lint.

There's lots of comments in the code, but the main gist of this commit
is that the acquisition of the global malloc lock on the
`wasm32-unknown-unknown` target when threads are enabled will not spin
on contention rather than block.

MIPS r6 is quite different with the previous version.
It use some new target triples:
  mipsisa32r6-unknown-linux-gnu
  mipsisa32r6el-unknown-linux-gnu
  mipsisa64r6-unknown-linux-gnuabi64
  mipsisa64r6el-unknown-linux-gnuabi64

This patch has been tested with Debian Port for mips64r6el,
and the support of these triples also is included in llvm:
  https://reviews.llvm.org/rGe58c45a695f39004710b6ce940d489fee800dbd3

A `Def::Variant` should be considered as a function in mir pretty
printing. Each variant has a constructor that we must print.

Given the following enum definition:

```
pub enum TestMe {
    X(usize),
}
```

We will need to generate a constructor for the variant `X` with a
signature that looks something like the following:

```
fn TestMe::X(_1: usize) -> TestMe;
```

Fix fallout from rust-lang#57667

…nkfelix

Make migrate mode work at item level granularity

Migrate mode now works entirely at the item level rather than the body level,
ensuring that we don't lose any errors in contained closures.

Closes rust-lang#58776

r? @pnkfelix

… r=sanxiyn

Update compiler_builtins to 0.1.7 to get windows/arm fix

librustc_interface: Update scoped-tls to 1.0

Done previously as a part of rust-lang#58748.

r? @Zoxc

…Mark-Simulacrum

Prevent cache issues on version updates

Fixes rust-lang#58827.

cc @rust-lang/infra

…oc, r=fitzgen

std: Spin for a global malloc lock on wasm32

There's lots of comments in the code, but the main gist of this commit
is that the acquisition of the global malloc lock on the
`wasm32-unknown-unknown` target when threads are enabled will not spin
on contention rather than block.

…rochenkov

Adds help message in error for invalid `impl for T` syntax

Fixes rust-lang#56031.

…henkov

Parse lifetimes that start with a number and give specific error

Fix rust-lang#58786.

core: ensure VaList passes improper_ctypes lint

Ensure the `core::ffi::VaList` structure passes the `improper_ctypes` lint.

Fixes: rust-lang#58280

MIPS: add r6 support

MIPS r6 is quite different with the previous version.
It use some new target triples:
  mipsisa32r6-unknown-linux-gnu
  mipsisa32r6el-unknown-linux-gnu
  mipsisa64r6-unknown-linux-gnuabi64
  mipsisa64r6el-unknown-linux-gnuabi64

This patch has been tested with Debian Port for mips64r6el,
and the support of these triples also is included in llvm:
  https://reviews.llvm.org/rGe58c45a695f39004710b6ce940d489fee800dbd3

…twco

When encountetring `||{}()`, suggest the likely intended `(||{})()`

Fix rust-lang#55851.

Fix ICE in MIR pretty printing

A `Def::Variant` should be considered as a function in mir pretty
printing. Each variant has a constructor that we must print.

Given the following enum definition:

```rust
pub enum TestMe {
    X(usize),
}
```

We will need to generate a constructor for the variant `X` with a
signature that looks something like the following:

```
fn TestMe::X(_1: usize) -> TestMe;
```

Fixes: rust-lang#59021

resolve: Account for new importable entities

Fixes the ICE encountered in rust-lang#58837
r? @Centril

…ackler

Use lifetime contravariance to elide more lifetimes in core+alloc+std

Sample:
```diff
-    impl<'a, 'b, A: ?Sized, B: ?Sized> PartialEq<&'b mut B> for &'a mut A where A: PartialEq<B> {
+    impl<A: ?Sized, B: ?Sized> PartialEq<&mut B> for &mut A where A: PartialEq<B> {
         #[inline]
-        fn eq(&self, other: &&'b mut B) -> bool { PartialEq::eq(*self, *other) }
+        fn eq(&self, other: &&mut B) -> bool { PartialEq::eq(*self, *other) }
         #[inline]
-        fn ne(&self, other: &&'b mut B) -> bool { PartialEq::ne(*self, *other) }
+        fn ne(&self, other: &&mut B) -> bool { PartialEq::ne(*self, *other) }
     }
```

[I didn't know this worked](https://internals.rust-lang.org/t/why-can-you-use-different-unconstrained-lifetimes-to-implement-traits/9544/2?u=scottmcm) until recently, but since defining methods contravariantly in their lifetimes this way has worked back to Rust 1.0, we might as well take advantage of combining it with IHLE.

we can now skip should_panic tests with the libtest harness