Fix incorrect use of compile_fail

`compile_fail` should only be used when the code is meant to show what *not* to do. In other words, there should be a fundamental flaw in the code. However, in this case, the example is just incomplete, so we should use `ignore` to avoid confusing readers.
rust-lang · matthiaskrgr · Feb 13, 2024 · Feb 13, 2024 · Feb 13, 2024 · Jan 30, 2024
commit cd3ba4a8852b20ba6aaa55db20bb415d4333c7c7
diff --git a/library/std/src/process.rs b/library/std/src/process.rs
@@ -171,7  171,7 @@ pub struct Child {
     /// The handle for writing to the child's standard input (stdin), if it
     /// has been captured. You might find it helpful to do
     ///
-    /// ```compile_fail,E0425
     /// ```ignore (incomplete)
     /// let stdin = child.stdin.take().unwrap();
     /// ```
     ///
@@ -183,7  183,7 @@ pub struct Child {
     /// The handle for reading from the child's standard output (stdout), if it
     /// has been captured. You might find it helpful to do
     ///
-    /// ```compile_fail,E0425
     /// ```ignore (incomplete)
     /// let stdout = child.stdout.take().unwrap();
     /// ```
     ///
@@ -195,7  195,7 @@ pub struct Child {
     /// The handle for reading from the child's standard error (stderr), if it
     /// has been captured. You might find it helpful to do
     ///
-    /// ```compile_fail,E0425
     /// ```ignore (incomplete)
     /// let stderr = child.stderr.take().unwrap();
     /// ```
     ///