diff --git a/src/tools/run-make-support/src/lib.rs b/src/tools/run-make-support/src/lib.rs
index b920f9a07db87..6a89a75d71591 100644
--- a/src/tools/run-make-support/src/lib.rs
+++ b/src/tools/run-make-support/src/lib.rs
@@ -169,6 +169,38 @@ pub fn cwd() -> PathBuf {
     env::current_dir().unwrap()
 }
 
+// FIXME(Oneirical): This will no longer be required after compiletest receives the ability
+// to manipulate read-only files. See https://github.com/rust-lang/rust/issues/126334
+/// Ensure that the path P is read-only while the test runs, and restore original permissions
+/// at the end so compiletest can clean up.
+/// This will panic on Windows if the path is a directory (as it would otherwise do nothing)
+#[track_caller]
+pub fn test_while_readonly<P: AsRef<Path>, F: FnOnce() + std::panic::UnwindSafe>(
+    path: P,
+    closure: F,
+) {
+    let path = path.as_ref();
+    if is_windows() && path.is_dir() {
+        eprintln!("This helper function cannot be used on Windows to make directories readonly.");
+        eprintln!(
+            "See the official documentation:
+            https://doc.rust-lang.org/std/fs/struct.Permissions.html#method.set_readonly"
+        );
+        panic!("`test_while_readonly` on directory detected while on Windows.");
+    }
+    let metadata = fs_wrapper::metadata(&path);
+    let original_perms = metadata.permissions();
+
+    let mut new_perms = original_perms.clone();
+    new_perms.set_readonly(true);
+    fs_wrapper::set_permissions(&path, new_perms);
+
+    let success = std::panic::catch_unwind(closure);
+
+    fs_wrapper::set_permissions(&path, original_perms);
+    success.unwrap();
+}
+
 /// Use `cygpath -w` on a path to get a Windows path string back. This assumes that `cygpath` is
 /// available on the platform!
 #[track_caller]
diff --git a/src/tools/tidy/src/allowed_run_make_makefiles.txt b/src/tools/tidy/src/allowed_run_make_makefiles.txt
index ac89a30f35342..0d7951bcfffc0 100644
--- a/src/tools/tidy/src/allowed_run_make_makefiles.txt
+++ b/src/tools/tidy/src/allowed_run_make_makefiles.txt
@@ -66,7 +66,6 @@ run-make/foreign-double-unwind/Makefile
 run-make/foreign-exceptions/Makefile
 run-make/foreign-rust-exceptions/Makefile
 run-make/glibc-staticlib-args/Makefile
-run-make/inaccessible-temp-dir/Makefile
 run-make/include_bytes_deps/Makefile
 run-make/incr-add-rust-src-component/Makefile
 run-make/incr-foreign-head-span/Makefile
@@ -79,7 +78,6 @@ run-make/invalid-library/Makefile
 run-make/invalid-so/Makefile
 run-make/invalid-staticlib/Makefile
 run-make/issue-107094/Makefile
-run-make/issue-10971-temps-dir/Makefile
 run-make/issue-109934-lto-debuginfo/Makefile
 run-make/issue-14698/Makefile
 run-make/issue-15460/Makefile
@@ -158,7 +156,6 @@ 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
 run-make/override-aliased-flags/Makefile
 run-make/overwrite-input/Makefile
 run-make/panic-abort-eh_frame/Makefile
diff --git a/tests/run-make/inaccessible-temp-dir/Makefile b/tests/run-make/inaccessible-temp-dir/Makefile
deleted file mode 100644
index abdba4eb86145..0000000000000
--- a/tests/run-make/inaccessible-temp-dir/Makefile
+++ /dev/null
@@ -1,32 +0,0 @@
-# only-linux
-# ignore-arm - linker error on `armhf-gnu`
-
-include ../tools.mk
-
-# Issue #66530: We would ICE if someone compiled with `-o /dev/null`,
-# because we would try to generate auxiliary files in `/dev/` (which
-# at least the OS X file system rejects).
-#
-# An attempt to `-Ztemps-dir` into a directory we cannot write into should
-# indeed be an error; but not an ICE.
-#
-# However, some folks run tests as root, which can write `/dev/` and end
-# up clobbering `/dev/null`. Instead we'll use an inaccessible path, which
-# also used to ICE, but even root can't magically write there.
-#
-# Note that `-Ztemps-dir` uses `create_dir_all` so it is not sufficient to
-# use a directory with non-existing parent like `/does-not-exist/output`.
-
-all:
-	# Create an inaccessible directory
-	mkdir $(TMPDIR)/inaccessible
-	chmod 000 $(TMPDIR)/inaccessible
-
-	# Run rustc with `-Ztemps-dir` set to a directory 
-	# *inside* the inaccessible one, so that it can't create it
-	$(RUSTC) program.rs -Ztemps-dir=$(TMPDIR)/inaccessible/tmp 2>&1 \
-		| $(CGREP) 'failed to find or create the directory specified by `--temps-dir`'
-
-	# Make the inaccessible directory accessible,
-	# so that compiletest can delete the temp dir
-	chmod +rw $(TMPDIR)/inaccessible
diff --git a/tests/run-make/inaccessible-temp-dir/rmake.rs b/tests/run-make/inaccessible-temp-dir/rmake.rs
new file mode 100644
index 0000000000000..be24e47b6decc
--- /dev/null
+++ b/tests/run-make/inaccessible-temp-dir/rmake.rs
@@ -0,0 +1,38 @@
+// Issue #66530: We would ICE if someone compiled with `-o /dev/null`,
+// because we would try to generate auxiliary files in `/dev/` (which
+// at least the OS X file system rejects).
+//
+// An attempt to `-Ztemps-dir` into a directory we cannot write into should
+// indeed be an error; but not an ICE.
+//
+// However, some folks run tests as root, which can write `/dev/` and end
+// up clobbering `/dev/null`. Instead we'll use an inaccessible path, which
+// also used to ICE, but even root can't magically write there.
+//
+// Note that `-Ztemps-dir` uses `create_dir_all` so it is not sufficient to
+// use a directory with non-existing parent like `/does-not-exist/output`.
+// See https://github.com/rust-lang/rust/issues/66530
+
+//@ ignore-arm
+// Reason: linker error on `armhf-gnu`
+//@ ignore-windows
+// Reason: `set_readonly` has no effect on directories
+// and does not prevent modification.
+
+use run_make_support::{fs_wrapper, rustc, test_while_readonly};
+
+fn main() {
+    // Create an inaccessible directory.
+    fs_wrapper::create_dir("inaccessible");
+    test_while_readonly("inaccessible", || {
+        // Run rustc with `-Z temps-dir` set to a directory *inside* the inaccessible one,
+        // so that it can't create `tmp`.
+        rustc()
+            .input("program.rs")
+            .arg("-Ztemps-dir=inaccessible/tmp")
+            .run_fail()
+            .assert_stderr_contains(
+                "failed to find or create the directory specified by `--temps-dir`",
+            );
+    });
+}
diff --git a/tests/run-make/issue-10971-temps-dir/Makefile b/tests/run-make/issue-10971-temps-dir/Makefile
deleted file mode 100644
index 6e1649a58d231..0000000000000
--- a/tests/run-make/issue-10971-temps-dir/Makefile
+++ /dev/null
@@ -1,10 +0,0 @@
-include ../tools.mk
-
-# Regression test for issue #10971
-# Running two invocations in parallel would overwrite each other's temp files.
-
-all:
-	touch $(TMPDIR)/lib.rs
-
-	$(RUSTC) --crate-type=lib -Z temps-dir=$(TMPDIR)/temp1 $(TMPDIR)/lib.rs & \
-	$(RUSTC) --crate-type=staticlib -Z temps-dir=$(TMPDIR)/temp2 $(TMPDIR)/lib.rs
diff --git a/tests/run-make/output-with-hyphens/Makefile b/tests/run-make/output-with-hyphens/Makefile
deleted file mode 100644
index 846c9a66a89a0..0000000000000
--- a/tests/run-make/output-with-hyphens/Makefile
+++ /dev/null
@@ -1,8 +0,0 @@
-# ignore-cross-compile
-include ../tools.mk
-
-all:
-	$(RUSTC) foo-bar.rs --crate-type bin
-	[ -f $(TMPDIR)/$(call BIN,foo-bar) ]
-	$(RUSTC) foo-bar.rs --crate-type lib
-	[ -f $(TMPDIR)/libfoo_bar.rlib ]
diff --git a/tests/run-make/output-with-hyphens/rmake.rs b/tests/run-make/output-with-hyphens/rmake.rs
new file mode 100644
index 0000000000000..79deb772bc5df
--- /dev/null
+++ b/tests/run-make/output-with-hyphens/rmake.rs
@@ -0,0 +1,17 @@
+// Rust files with hyphens in their filename should
+// not result in compiled libraries keeping that hyphen -
+// it should become an underscore. Only bin executables
+// should keep the hyphen. This test ensures that this rule
+// remains enforced.
+// See https://github.com/rust-lang/rust/pull/23786
+
+//@ ignore-cross-compile
+
+use run_make_support::{bin_name, path, rust_lib_name, rustc};
+
+fn main() {
+    rustc().input("foo-bar.rs").crate_type("bin").run();
+    assert!(path(bin_name("foo-bar")).exists());
+    rustc().input("foo-bar.rs").crate_type("lib").run();
+    assert!(path(rust_lib_name("foo_bar")).exists());
+}
diff --git a/tests/run-make/parallel-rustc-no-overwrite/rmake.rs b/tests/run-make/parallel-rustc-no-overwrite/rmake.rs
new file mode 100644
index 0000000000000..3f032cf3762a9
--- /dev/null
+++ b/tests/run-make/parallel-rustc-no-overwrite/rmake.rs
@@ -0,0 +1,25 @@
+// When two instances of rustc are invoked in parallel, they
+// can conflict on their temporary files and overwrite each others',
+// leading to unsuccessful compilation. The -Z temps-dir flag adds
+// separate designated directories for each rustc invocation, preventing
+// conflicts. This test uses this flag and checks for successful compilation.
+// See https://github.com/rust-lang/rust/pull/83846
+
+use run_make_support::{fs_wrapper, rustc};
+use std::sync::{Arc, Barrier};
+use std::thread;
+
+fn main() {
+    fs_wrapper::create_file("lib.rs");
+    let barrier = Arc::new(Barrier::new(2));
+    let handle = {
+        let barrier = Arc::clone(&barrier);
+        thread::spawn(move || {
+            barrier.wait();
+            rustc().crate_type("lib").arg("-Ztemps-dir=temp1").input("lib.rs").run();
+        })
+    };
+    barrier.wait();
+    rustc().crate_type("staticlib").arg("-Ztemps-dir=temp2").input("lib.rs").run();
+    handle.join().expect("lib thread panicked");
+}