I've moved all intrinsics in a single file (libcore/private/intrinsics.rs) and changed a few files to make use of this file (e.g. vec.rs: move_val_init).

Two intrinsics have been commented out:
visit_tydesc: it uses TyDesc and TyVisitor, this would create a dependency on librustc which seems undesirable.
frame_address: I really had no idea what it should look like without the legacy modes (would it even work? In several places in libcore the (legacy-modes) intrinsics were wrapped
with a normal fn) and what it was supposed to do.

Some documentation is still required, but many names are fairly self-explanatory.

Closes Issue4903

fixes rust-lang#4903.

Check list:
- [x] Followed [lint naming conventions][lint_naming]
- [x] Added passing UI tests (including committed `.stderr` file)
- [x] `cargo test` passes locally
- [x] Executed `./util/dev update_lints`
- [x] Added lint documentation
- [x] Run `./util/dev fmt`

[lint_naming]: https://rust-lang.github.io/rfcs/0344-conventions-galore.html#lints
---

changelog: implement lint that warn about single component path imports(`use ident;`).

…adics, r=RalfJung,folkertdev

Disable retagging for variadic arguments in const-eval

Fixes [rust-lang#5058](rust-lang/miri#5058) in Miri.

Retags occur on typed copies, which happen when we pass variadic arguments to a function. At the moment, variadic arguments receive `RetagMode::FnEntry` retags, which protects their permissions for the duration of the call. However, protection needs to be based on callee-side information, and the callee has now way of knowing what's contained within its `VaList`.

This PR disables retagging entirely when copying variable arguments. It also adds a new, passing test case that would originally fail before this change.

cc: @RalfJung, @folkertdev

…adics, r=RalfJung,folkertdev

Disable retagging for variadic arguments in const-eval

Fixes [rust-lang#5058](rust-lang/miri#5058) in Miri.

Retags occur on typed copies, which happen when we pass variadic arguments to a function. At the moment, variadic arguments receive `RetagMode::FnEntry` retags, which protects their permissions for the duration of the call. However, protection needs to be based on callee-side information, and the callee has now way of knowing what's contained within its `VaList`.

This PR disables retagging entirely when copying variable arguments. It also adds a new, passing test case that would originally fail before this change.

cc: @RalfJung, @folkertdev

…adics, r=RalfJung,folkertdev

Disable retagging for variadic arguments in const-eval

Fixes [rust-lang#5058](rust-lang/miri#5058) in Miri.

Retags occur on typed copies, which happen when we pass variadic arguments to a function. At the moment, variadic arguments receive `RetagMode::FnEntry` retags, which protects their permissions for the duration of the call. However, protection needs to be based on callee-side information, and the callee has now way of knowing what's contained within its `VaList`.

This PR disables retagging entirely when copying variable arguments. It also adds a new, passing test case that would originally fail before this change.

cc: @RalfJung, @folkertdev

…adics, r=RalfJung,folkertdev

Disable retagging for variadic arguments in const-eval

Fixes [rust-lang#5058](rust-lang/miri#5058) in Miri.

Retags occur on typed copies, which happen when we pass variadic arguments to a function. At the moment, variadic arguments receive `RetagMode::FnEntry` retags, which protects their permissions for the duration of the call. However, protection needs to be based on callee-side information, and the callee has now way of knowing what's contained within its `VaList`.

This PR disables retagging entirely when copying variable arguments. It also adds a new, passing test case that would originally fail before this change.

cc: @RalfJung, @folkertdev

…adics, r=RalfJung,folkertdev

Disable retagging for variadic arguments in const-eval

Fixes [rust-lang#5058](rust-lang/miri#5058) in Miri.

Retags occur on typed copies, which happen when we pass variadic arguments to a function. At the moment, variadic arguments receive `RetagMode::FnEntry` retags, which protects their permissions for the duration of the call. However, protection needs to be based on callee-side information, and the callee has now way of knowing what's contained within its `VaList`.

This PR disables retagging entirely when copying variable arguments. It also adds a new, passing test case that would originally fail before this change.

cc: @RalfJung, @folkertdev

Rollup merge of #157622 - BorrowSanitizer:ignore-retags-variadics, r=RalfJung,folkertdev

Disable retagging for variadic arguments in const-eval

Fixes [#5058](rust-lang/miri#5058) in Miri.

Retags occur on typed copies, which happen when we pass variadic arguments to a function. At the moment, variadic arguments receive `RetagMode::FnEntry` retags, which protects their permissions for the duration of the call. However, protection needs to be based on callee-side information, and the callee has now way of knowing what's contained within its `VaList`.

This PR disables retagging entirely when copying variable arguments. It also adds a new, passing test case that would originally fail before this change.

cc: @RalfJung, @folkertdev