`equatable-if-let` puts bindings outside of macro inside macro definition

Using the following flags

--force-warn clippy::equatable-if-let

this code:

//@ run-pass

// Check that it is possible to resolve, in the value namespace,
// to an `enum` variant through a type alias. This includes `Self`.
// Type qualified syntax `<Type>::Variant` also works when syntactically valid.

#[derive(Debug, PartialEq, Eq)]
enum Foo {
    Bar(i32),
    Baz { i: i32 },
    Qux,
}

type FooAlias = Foo;
type OptionAlias = Option<i32>;

macro_rules! check_pat {
    ($x:expr, $p:pat) => {
        assert!(if let $p = $x { true } else { false });
    };
}

impl Foo {
    fn bar() -> Self {
        let x = Self::Bar(3);
        assert_eq!(x, <Self>::Bar(3));
        check_pat!(x, Self::Bar(3));
        x
    }
}

fn main() {}

caused the following diagnostics:

    Checking _a v0.1.0 (/tmp/icemaker_global_tempdir.QlfkGs76BA87/icemaker_clippyfix_tempdir.lb9ooZZJhcpZ/_a)
warning: this pattern matching can be expressed using equality
  --> src/main.rs:19:20
   |
19 |         assert!(if let $p = $x { true } else { false });
   |                    ^^^^^^^^^^^ help: try: `x == Self::Bar(3)`
...
27 |         check_pat!(x, Self::Bar(3));
   |         --------------------------- in this macro invocation
   |
   = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#equatable_if_let
   = note: requested on the command line with `--force-warn clippy::equatable-if-let`
   = note: this warning originates in the macro `check_pat` (in Nightly builds, run with -Z macro-backtrace for more info)

warning: `_a` (bin "_a") generated 1 warning
    Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.23s

However after applying these diagnostics, the resulting code:

//@ run-pass

// Check that it is possible to resolve, in the value namespace,
// to an `enum` variant through a type alias. This includes `Self`.
// Type qualified syntax `<Type>::Variant` also works when syntactically valid.

#[derive(Debug, PartialEq, Eq)]
enum Foo {
    Bar(i32),
    Baz { i: i32 },
    Qux,
}

type FooAlias = Foo;
type OptionAlias = Option<i32>;

macro_rules! check_pat {
    ($x:expr, $p:pat) => {
        assert!(if x == Self::Bar(3) { true } else { false });
    };
}

impl Foo {
    fn bar() -> Self {
        let x = Self::Bar(3);
        assert_eq!(x, <Self>::Bar(3));
        check_pat!(x, Self::Bar(3));
        x
    }
}

fn main() {}

no longer compiled:

    Checking _a v0.1.0 (/tmp/icemaker_global_tempdir.QlfkGs76BA87/icemaker_clippyfix_tempdir.lb9ooZZJhcpZ/_a)
error[E0425]: cannot find value `x` in this scope
  --> src/main.rs:19:20
   |
19 |         assert!(if x == Self::Bar(3) { true } else { false });
   |                    ^ not found in this scope
...
27 |         check_pat!(x, Self::Bar(3));
   |         --------------------------- in this macro invocation
   |
help: an identifier with the same name exists, but is not accessible due to macro hygiene
  --> src/main.rs:25:13
   |
25 |         let x = Self::Bar(3);
   |             ^
   = note: this error originates in the macro `check_pat` (in Nightly builds, run with -Z macro-backtrace for more info)

For more information about this error, try `rustc --explain E0425`.
error: could not compile `_a` (bin "_a") due to 1 previous error
warning: build failed, waiting for other jobs to finish...
error: could not compile `_a` (bin "_a" test) due to 1 previous error

Version:

rustc 1.93.0-nightly (8a3a6bdb6 2025-11-29)
binary: rustc
commit-hash: 8a3a6bdb68b4d4c9ed922840808b02015741331e
commit-date: 2025-11-29
host: x86_64-unknown-linux-gnu
release: 1.93.0-nightly
LLVM version: 21.1.5

Start with the equatable-if-let lint and reproduce the reported macro_rules! case using the code in the issue. Trace how the diagnostic suggestion handles bindings from macro arguments, then verify that the suggested result preserves macro hygiene and compiles.