Auto merge of #128651 - folkertdev:naked-asm-macro-v2, r=Amanieu

add `naked_asm!` macro for use in `#[naked]` functions

tracking issue: https://github.com/rust-lang/rust/issues/90957

Adds the `core::arch::naked_asm` macro, to be used in `#[naked]` functions, but providing better error messages and a place to explain the restrictions on assembly in naked functions.

This PR does not yet require that the `naked_asm!` macro is used inside of `#[naked]` functions:

- the `asm!` macro can still be used in `#[naked]` functions currently, with the same restrictions and error messages as before.
- the `naked_asm!` macro can be used outside of `#[naked]` functions. It has not yet been decided whether that should be allowed long-term.

In this PR, the parsing code of `naked_asm!` now enforces the restrictions on assembly in naked functions, with the exception of checking that the `noreturn` option is specified. It also has not currently been decided if `noreturn` should be implicit or not.

This PR looks large because it touches a bunch of tests. The code changes are mostly straightforward I think: we now have 3 flavors of assembly macro, and that information must be propagated through the parsing code and error messages.

cc `@Lokathor`

r? `@Amanieu`

compiler/rustc_lint_defs/src/builtin.rs

@@ -2925,16 +2925,16 @@ declare_lint! {
     /// ```rust
     /// #![feature(asm_experimental_arch, naked_functions)]
     ///
-    /// use std::arch::asm;
+    /// use std::arch::naked_asm;
     ///
     /// #[naked]
     /// pub fn default_abi() -> u32 {
-    ///     unsafe { asm!("", options(noreturn)); }
+    ///     unsafe { naked_asm!(""); }
     /// }
     ///
     /// #[naked]
     /// pub extern "Rust" fn rust_abi() -> u32 {
-    ///     unsafe { asm!("", options(noreturn)); }
+    ///     unsafe { naked_asm!(""); }
     /// }
     /// ```
     ///