Remove warnings/errors from compiler when using typeck_body in rustdoc span map builder

compiler/rustc_session/src/session.rs

@@ -500,6 +500,10 @@ impl Session {
         &self.parse_sess.span_diagnostic
     }
 
+    pub fn with_disabled_diagnostic<T, F: FnOnce() -> T>(&self, f: F) -> T {
+        self.parse_sess.span_diagnostic.with_disabled_diagnostic(f)
+    }
+
     /// Analogous to calling methods on the given `DiagnosticBuilder`, but
     /// deduplicates on lint ID, span (if any), and message for this `Session`
     fn diag_once<'a, 'b>(