rewrite output-filename-conflicts-with-directory to rmake

Author: Oneirical

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -152,7 +152,6 @@ run-make/no-duplicate-libs/Makefile
 run-make/obey-crate-type-flag/Makefile
 run-make/optimization-remarks-dir-pgo/Makefile
 run-make/optimization-remarks-dir/Makefile
-run-make/output-filename-conflicts-with-directory/Makefile
 run-make/output-filename-overwrites-input/Makefile
 run-make/output-type-permutations/Makefile
 run-make/output-with-hyphens/Makefile

tests/run-make/output-filename-conflicts-with-directory/Makefile

@@ -0,0 +1,11 @@
+// When the compiled executable would conflict with a directory, a
+// rustc error should be displayed instead of a verbose and
+// potentially-confusing linker error.
+// See https://github.com/rust-lang/rust/pull/47203
+
+use run_make_support::{fs_wrapper, rustc};
+
+fn main() {
+    fs_wrapper::create_dir("foo");
+    rustc().input("foo.rs").output("foo").run_fail().assert_stderr_contains(r#"the generated executable for the input file "foo.rs" conflicts with the existing directory "foo""#);
+}