This restricts instructions to those offered by Pentium,
to support e.g. AMD Geode.

There is already an entry for this target in the NetBSD
platform support page at

  src/doc/rustc/src/platform-support/netbsd.md

...so this should forestall its removal.

Additional fixes are needed for some vendored modules, this
is the changes in the rust compiler core itself.

...explaining why we need -latomic (gcc & g++ built for i486,
and LLVM insisting on use of 64-bit atomics).

CC rust-lang#89566.

… fields

Fix rust-lang#22488.

Suggest assoc fn `new` when trying to build tuple struct with private fields

Fix rust-lang#22488.

Tweak suggestion span for outer attr and point at item following invalid inner attr

After:

```
error: `unix_sigpipe` attribute cannot be used at crate level
  --> $DIR/unix_sigpipe-crate.rs:2:1
   |
LL | #![unix_sigpipe = "inherit"]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
LL |
LL | fn main() {}
   | ------------ the inner attribute doesn't annotate this function
   |
help: perhaps you meant to use an outer attribute
   |
LL - #![unix_sigpipe = "inherit"]
LL + #[unix_sigpipe = "inherit"]
   |
```

Before:

```
error: `unix_sigpipe` attribute cannot be used at crate level
  --> $DIR/unix_sigpipe-crate.rs:2:1
   |
LL | #![unix_sigpipe = "inherit"]
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
   |
help: perhaps you meant to use an outer attribute
   |
LL | #[unix_sigpipe = "inherit"]
   | ~~~~~~~~~~~~~~~~~~~~~~~~~~~
```

CC rust-lang#89566.

…pl, r=petrochenkov

Cleanup and improve `--check-cfg` implementation

This PR removes some indentation in the code, as well as preventing some bugs/misusages and fix a nit in the doc.

r? `@petrochenkov` (maybe)

Add support for i586-unknown-netbsd as target.

This restricts instructions to those offered by Pentium, to support e.g. AMD Geode.

There is already an entry for this target in the NetBSD platform support page at

  src/doc/rustc/src/platform-support/netbsd.md

...so this should forestall its removal.

Additional fixes are needed for some vendored modules, this is the changes in the rust compiler core itself.

…llect-into-fix-typo, r=the8472

Fix documentation typo in std::iter::Iterator::collect_into