Rewrite and rename issue-22131 to rmake

Author: Oneirical

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -38,7 +38,6 @@ run-make/interdependent-c-libraries/Makefile
 run-make/issue-107094/Makefile
 run-make/issue-14698/Makefile
 run-make/issue-15460/Makefile
-run-make/issue-22131/Makefile
 run-make/issue-26006/Makefile
 run-make/issue-28595/Makefile
 run-make/issue-33329/Makefile

tests/run-make/issue-22131/Makefile

@@ -0,0 +1,19 @@
+// A rustdoc bug caused the `feature=bar` syntax for the cfg flag to be interpreted
+// wrongly, with `feature=bar` instead of just `bar` being understood as the feature name.
+// After this was fixed in #22135, this test checks that this bug does not make a resurgence.
+// See https://github.com/rust-lang/rust/issues/22131
+
+//FIXME(Oneirical): try test-various
+
+use run_make_support::{rustc, rustdoc};
+
+fn main() {
+    rustc().cfg(r#"feature="bar""#).crate_type("lib").input("foo.rs").run();
+    rustdoc()
+        .arg("--test")
+        .arg("--cfg")
+        .arg(r#"feature="bar""#)
+        .input("foo.rs")
+        .run()
+        .assert_stdout_contains("foo.rs - foo (line 1) ... ok");
+}