Add new Rustdoc::emit method in run-make-support

src/tools/run-make-support/src/external_deps/rustdoc.rs

@@ -132,4 +132,11 @@ impl Rustdoc {
         self.cmd.arg(format);
         self
     }
+
+    /// Specify type(s) of output files to generate.
+    pub fn emit<S: AsRef<str>>(&mut self, kinds: S) -> &mut Self {
+        let kinds = kinds.as_ref();
+        self.cmd.arg(format!("--emit={kinds}"));
+        self
+    }
 }