This fixes warning when building Rust and running tests:
```
warning: library kind `static-nobundle` has been superseded by specifying `-bundle` on library kind `static`. Try `static:-bundle`
warning: `rustc_llvm` (lib) generated 2 warnings (1 duplicate)
```

The makes the heading / documentation distinction clearer.

Normalize MIR with RevealAll before optimizations.

Fixes rust-lang#78442

Add rustc lint, warning when iterating over hashmaps

r? rust-lang/wg-incr-comp

…ietroalbini

Skip documentation for tier 2 targets on dist-x86_64-apple-darwin

I don't have an easy way to test this locally, but I believe it should work. Based on one log result should shave ~14 minutes off the dist-x86_64-apple builder (doesn't help with aarch64 dist or x86_64 test builder, so not actually decreasing total CI time most likely).

r? `@pietroalbini`

…mez,camelid

Fix alignment of method headings for scannability

We sometimes use indentation to indicate something is a heading: The section that comes after is indented by 24px relative to the heading. However, the relationship between the "Implementations" section heading, the `impl` headings it contains, and the `pub fn` subheadings within each impl, is awkward. It goes **Implementations**, 15px indent, `impl`, 5px indent, `pub fn`, 4px indent, docblock.

I line up `impl` and `pub fn` with the `Implementations` heading, give `impl` a larger font size to indicate it is higher in the hierarchy, and indent the docblock a full 24px relative to their parent, matching the indents we use elsewhere to distinguish section headings. By letting the `pub fn` stick out to the left of the docblock, I think this makes methods significantly more scannable.

Related to rust-lang#59829

r? `@camelid`

[Old](https://doc.rust-lang.org/nightly/std/string/struct.String.html#implementations):

[![image](https://user-images.githubusercontent.com/220205/138380233-9c63a0f2-0f80-40a3-ab3d-a1ee9fb7c5d8.png)](https://doc.rust-lang.org/nightly/std/string/struct.String.html#implementations)

[New](https://jacob.hoffman-andrews.com/rust/outdent-methods/std/string/struct.String.html#implementations):

[![image](https://user-images.githubusercontent.com/220205/138392479-b45fce3f-bf43-42e0-81ee-c4bb9ac35cda.png)](https://jacob.hoffman-andrews.com/rust/outdent-methods/std/string/struct.String.html#implementations)

…petrochenkov

Repace use of `static_nobundle` with `native_link_modifiers` within Rust codebase

This fixes warnings when building Rust and running tests:
```
warning: library kind `static-nobundle` has been superseded by specifying `-bundle` on library kind `static`. Try `static:-bundle`
warning: `rustc_llvm` (lib) generated 2 warnings (1 duplicate)
```