rewrite compiler-lookup-paths-2 to rmake

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -6,7 +6,6 @@ run-make/c-static-rlib/Makefile
 run-make/c-unwind-abi-catch-lib-panic/Makefile
 run-make/cat-and-grep-sanity-check/Makefile
 run-make/cdylib-dylib-linkage/Makefile
-run-make/compiler-lookup-paths-2/Makefile
 run-make/compiler-rt-works-on-mingw/Makefile
 run-make/crate-hash-rustc-version/Makefile
 run-make/cross-lang-lto-clang/Makefile

tests/run-make/compiler-lookup-paths-2/rmake.rs

@@ -0,0 +1,20 @@
+// This test checks that extern crate declarations in Cargo without a corresponding declaration
+// in the manifest of a dependency are NOT allowed. The last rustc call does it anyways, which
+// should result in a compilation failure.
+// See https://github.com/rust-lang/rust/pull/21113
+
+use run_make_support::{path, rfs, rust_lib_name, rustc};
+
+fn main() {
+    rfs::create_dir("a");
+    rfs::create_dir("b");
+    rustc().input("a.rs").run();
+    rfs::rename(rust_lib_name("a"), path("a").join(rust_lib_name("a")));
+    rustc().input("b.rs").library_search_path("a").run();
+    rfs::rename(rust_lib_name("b"), path("b").join(rust_lib_name("b")));
+    rustc()
+        .input("c.rs")
+        .library_search_path("crate=b")
+        .library_search_path("dependency=a")
+        .run_fail();
+}

tests/run-make/test-benches/rmake.rs

@@ -13,6 +13,7 @@
 use run_make_support::{run, run_with_args, rustc};
 
 fn main() {
+    // Smoke-test that #[bench] isn't entirely broken.
     rustc().arg("--test").input("smokebench.rs").opt().run();
     run_with_args("smokebench", &["--bench"]);
     run_with_args("smokebench", &["--bench", "noiter"]);