Add support for Arm64 Catalyst on ARM Macs
This is an iteration on https://github.com/rust-lang/rust/pull/63467 which was merged a while ago. In the aforementioned PR, I added support for the `X86_64-apple-ios-macabi` target triple, which is Catalyst, iOS apps running on macOS.
Very soon, Apple will launch ARM64 based Macs which will introduce `aarch64_apple_darwin.rs`, macOS apps using the Darwin ABI running on ARM. This PR adds support for Catalyst apps on ARM Macs: iOS apps compiled for the darwin ABI.
I don't have access to a Apple Developer Transition Kit (DTK), so I can't really test if the generated binaries work correctly. I'm vaguely hopeful that somebody with access to a DTK could give this a spin.
This preserves the current lint behavior for now.
Linting after item statements currently prevents the compiler from bootstrapping.
Fixing this is blocked on fixing this upstream in Cargo, and bumping the Cargo
submodule.
Loading a macro from libstd causes us to load serialized
`SyntaxContext`s in a platform-dependent way, causing the printed spans
to differ between platforms.
When parsing a statement (e.g. inside a function body),
we now consider `struct Foo {};` and `$stmt;` to each consist
of two statements: `struct Foo {}` and `;`, and `$stmt` and `;`.
As a result, an attribute macro invoke as
`fn foo() { #[attr] struct Bar{}; }` will see `struct Bar{}` as its
input. Additionally, the 'unused semicolon' lint now fires in more
places.
We now collect tokens for the underlying node wrapped by `StmtKind`
instead of storing tokens directly in `Stmt`.
`LazyTokenStream` now supports capturing a trailing semicolon after it
is initially constructed. This allows us to avoid refactoring statement
parsing to wrap the parsing of the semicolon in `parse_tokens`.
Attributes on item statements
(e.g. `fn foo() { #[bar] struct MyStruct; }`) are now treated as
item attributes, not statement attributes, which is consistent with how
we handle attributes on other kinds of statements. The feature-gating
code is adjusted so that proc-macro attributes are still allowed on item
statements on stable.
Two built-in macros (`#[global_allocator]` and `#[test]`) needed to be
adjusted to support being passed `Annotatable::Stmt`.
