rewrite overwrite-input to rmake

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -119,7 +119,6 @@ run-make/optimization-remarks-dir-pgo/Makefile
 run-make/optimization-remarks-dir/Makefile
 run-make/output-type-permutations/Makefile
 run-make/override-aliased-flags/Makefile
-run-make/overwrite-input/Makefile
 run-make/panic-abort-eh_frame/Makefile
 run-make/pass-linker-flags-flavor/Makefile
 run-make/pass-linker-flags-from-dep/Makefile

tests/run-make/overwrite-input/file.stderr

@@ -1,6 +1,4 @@
-warning: ignoring --out-dir flag due to -o flag
-
 error: the input file "main.rs" would be overwritten by the generated executable
 
-error: aborting due to 1 previous error; 1 warning emitted
+error: aborting due to 1 previous error
 

tests/run-make/overwrite-input/folder.stderr

@@ -1,6 +1,4 @@
-warning: ignoring --out-dir flag due to -o flag
-
 error: the generated executable for the input file "main.rs" conflicts with the existing directory "."
 
-error: aborting due to 1 previous error; 1 warning emitted
+error: aborting due to 1 previous error
 

tests/run-make/overwrite-input/rmake.rs

@@ -0,0 +1,13 @@
+// An attempt to set the output `-o` into a directory or a file we cannot write into should indeed
+// be an error; but not an ICE (Internal Compiler Error). This test attempts both and checks
+// that the standard error matches what is expected.
+// See https://github.com/rust-lang/rust/issues/66530
+
+use run_make_support::{diff, rustc};
+
+fn main() {
+    let file_out = rustc().input("main.rs").output("main.rs").run_fail().stderr_utf8();
+    let folder_out = rustc().input("main.rs").output(".").run_fail().stderr_utf8();
+    diff().expected_file("file.stderr").actual_text("actual-file-stderr", file_out).run();
+    diff().expected_file("folder.stderr").actual_text("actual-folder-stderr", folder_out).run();
+}