Co-authored-by: Jakub Beránek <berykubik@gmail.com>

Update the minimum external LLVM to 14

With this change, we'll have stable support for LLVM 14 through 16 (pending release).
For reference, the previous increase to LLVM 13 was rust-lang#100460.

Fix `x fix` on the standard library itself

Fixes rust-lang#107501

update ICU4X to 1.1.0

This patch updates the ICU4X crates to version 1.1.0 and regenerates the static data for `rustc_baked_icu_data`.

This is mostly an internal and bugfix update. It notably includes unicode-org/icu4x#2834 to fix the future compatibility warning for [`BYTE_SLICE_IN_PACKED_STRUCT_WITH_DERIVE`](rust-lang#107457).

[full changelog](https://github.com/unicode-org/icu4x/blob/icu%401.1.0/CHANGELOG.md)

…imulacrum

Store metrics from `metrics.json` to CI PGO timer

With this change, we'll be able to easily see how long does it take to compile LLVM vs `rustc`.

r? ```@Mark-Simulacrum```

…ilstrieb

Use `is_str` instead of string kind comparison

Split out from rust-lang#107939

…errors

add an unstable `#[rustc_coinductive]` attribute

useful to test coinduction, especially in the new solver.

as this attribute should remain permanently unstable I don't think this needs any official approval. cc ``@rust-lang/types``

had to weaken the check for stable query results in the solver to prevent an ICE if there's a coinductive cycle with constraints.

r? ``@compiler-errors``

…tors, r=oli-obk

Refactor refcounted structural_impls via functors

The mapping of values in refcounted types can be extracted as a functor, simplifying the implementations in the type library (whose structural folding impls now all use such functors).  This functor could also prove more generally useful elsewhere.

…g_traversals, r=oli-obk

Use derive attributes for uninteresting traversals

It appears that visiting and folding was implemented on `BitMatrix` solely so that the derive macros could be used on `GeneratorLayout`, however such implementation would not necessarily be correct for other uses (if there were any).  Adding attributes to the derive macro is more correct and potentially more generally useful.

r? ``@oli-obk``

interpret: rename Pointer::from_addr → from_addr_invalid

This function corresponds to `ptr::invalid` in the standard library; the previous name was not clear enough IMO.