test: avoid running rustfix on leaked writeln macro internals test

This test contains conflicting MaybeIncorrect suggestions which will
cause the fixed file to not compile.

tests/ui/typeck/issue-112007-leaked-writeln-macro-internals.fixed

@@ -1,37 +0,0 @@
-//@ run-rustfix
-#![allow(dead_code)]
-
-// https://github.com/rust-lang/rust/issues/112007
-fn bug_report<W: std::fmt::Write>(w: &mut W) -> std::fmt::Result {
-    if true {
-        writeln!(w, "`;?` here ->")?;
-    } else {
-        return writeln!(w, "but not here");
-        //~^ ERROR mismatched types
-    };
-    Ok(())
-}
-
-macro_rules! baz {
-    ($w: expr) => {
-        bar!($w)
-    }
-}
-
-macro_rules! bar {
-    ($w: expr) => {
-        writeln!($w, "but not here")
-        //~^ ERROR mismatched types
-    }
-}
-
-fn foo<W: std::fmt::Write>(w: &mut W) -> std::fmt::Result {
-    if true {
-        writeln!(w, "`;?` here ->")?;
-    } else {
-        return baz!(w);
-    };
-    Ok(())
-}
-
-fn main() {}

tests/ui/typeck/issue-112007-leaked-writeln-macro-internals.rs

@@ -1,8 +1,16 @@
-//@ run-rustfix
-#![allow(dead_code)]
+// Check that we don't leak stdlib implementation details through suggestions.
+// Also check that the suggestion provided tries as hard as it can to see through local macros.
+//
+// FIXME(jieyouxu): this test is NOT run-rustfix because this test contains conflicting
+// MaybeIncorrect suggestions:
+//
+// 1. `return ... ;`
+// 2. `?`
+//
+// when the suggestions are applied to the same file, it becomes uncompilable.
 
 // https://github.com/rust-lang/rust/issues/112007
-fn bug_report<W: std::fmt::Write>(w: &mut W) -> std::fmt::Result {
+pub fn bug_report<W: std::fmt::Write>(w: &mut W) -> std::fmt::Result {
     if true {
         writeln!(w, "`;?` here ->")?;
     } else {
@@ -25,7 +33,7 @@ macro_rules! bar {
     }
 }
 
-fn foo<W: std::fmt::Write>(w: &mut W) -> std::fmt::Result {
+pub fn foo<W: std::fmt::Write>(w: &mut W) -> std::fmt::Result {
     if true {
         writeln!(w, "`;?` here ->")?;
     } else {
@@ -34,4 +42,4 @@ fn foo<W: std::fmt::Write>(w: &mut W) -> std::fmt::Result {
     Ok(())
 }
 
-fn main() {}
+pub fn main() {}

tests/ui/typeck/issue-112007-leaked-writeln-macro-internals.stderr

@@ -1,5 +1,5 @@
 error[E0308]: mismatched types
-  --> $DIR/issue-112007-leaked-writeln-macro-internals.rs:9:9
+  --> $DIR/issue-112007-leaked-writeln-macro-internals.rs:17:9
    |
 LL | /     if true {
 LL | |         writeln!(w, "`;?` here ->")?;
@@ -21,9 +21,13 @@ help: you might have meant to return this value
    |
 LL |         return writeln!(w, "but not here");
    |         ++++++                            +
+help: use the `?` operator to extract the `Result<(), std::fmt::Error>` value, propagating a `Result::Err` value to the caller
+   |
+LL |         writeln!(w, "but not here")?
+   |                                    +
 
 error[E0308]: mismatched types
-  --> $DIR/issue-112007-leaked-writeln-macro-internals.rs:32:9
+  --> $DIR/issue-112007-leaked-writeln-macro-internals.rs:40:9
    |
 LL | /     if true {
 LL | |         writeln!(w, "`;?` here ->")?;
@@ -44,6 +48,10 @@ help: you might have meant to return this value
    |
 LL |         return baz!(w);
    |         ++++++        +
+help: use the `?` operator to extract the `Result<(), std::fmt::Error>` value, propagating a `Result::Err` value to the caller
+   |
+LL |         writeln!($w, "but not here")?
+   |                                     +
 
 error: aborting due to 2 previous errors