Rollup merge of #123654 - jieyouxu:question-mark-span, r=Nadrieril

typeck: fix `?` suggestion span

Noticed in <https://github.com/rust-lang/rust/pull/112043#issuecomment-2043565292>, if the

```
use the `?` operator to extract the `Result<(), std::fmt::Error>` value, propagating a `Result::Err` value to the caller
```

suggestion is applied to a macro that comes from a non-local crate (e.g. the stdlib), the suggestion span can become non-local, which will cause newer rustfix versions to fail.

This PR tries to remedy the problem by recursively probing ancestors of the expression span, trying to identify the most ancestor span that is (1) still local, and (2) still shares the same syntax context as the expression.

This is the same strategy used in https://github.com/rust-lang/rust/pull/112043.

The test unfortunately cannot `//@ run-rustfix` because there are two conflicting MaybeIncorrect suggestions that when collectively applied, cause the fixed source file to become non-compilable.

Also avoid running `//@ run-rustfix` for `tests/ui/typeck/issue-112007-leaked-writeln-macro-internals.rs` because that also contains conflicting suggestions.

cc `@ehuss` who noticed this. This question mark span fix + not running rustfix on the tests containing conflicting MaybeIncorrect suggestions should hopefully unblock rustfix from updating.

compiler/rustc_span/src/lib.rs

@@ -743,6 +743,45 @@ impl Span {
         Some(self)
     }
 
+    /// Recursively walk down the expansion ancestors to find the oldest ancestor span with the same
+    /// [`SyntaxContext`] the initial span.
+    ///
+    /// This method is suitable for peeling through *local* macro expansions to find the "innermost"
+    /// span that is still local and shares the same [`SyntaxContext`]. For example, given
+    ///
+    /// ```ignore (illustrative example, contains type error)
+    ///  macro_rules! outer {
+    ///      ($x: expr) => {
+    ///          inner!($x)
+    ///      }
+    ///  }
+    ///
+    ///  macro_rules! inner {
+    ///      ($x: expr) => {
+    ///          format!("error: {}", $x)
+    ///          //~^ ERROR mismatched types
+    ///      }
+    ///  }
+    ///
+    ///  fn bar(x: &str) -> Result<(), Box<dyn std::error::Error>> {
+    ///      Err(outer!(x))
+    ///  }
+    /// ```
+    ///
+    /// if provided the initial span of `outer!(x)` inside `bar`, this method will recurse
+    /// the parent callsites until we reach `format!("error: {}", $x)`, at which point it is the
+    /// oldest ancestor span that is both still local and shares the same [`SyntaxContext`] as the
+    /// initial span.
+    pub fn find_oldest_ancestor_in_same_ctxt(self) -> Span {
+        let mut cur = self;
+        while cur.eq_ctxt(self)
+            && let Some(parent_callsite) = cur.parent_callsite()
+        {
+            cur = parent_callsite;
+        }
+        cur
+    }
+
     /// Edition of the crate from which this span came.
     pub fn edition(self) -> edition::Edition {
         self.ctxt().edition()