Migrate wasm-exceptions-nostd to rmake

src/tools/tidy/src/allowed_run_make_makefiles.txt

@@ -186,5 +186,4 @@ run-make/track-pgo-dep-info/Makefile
 run-make/translation/Makefile
 run-make/type-mismatch-same-crate-name/Makefile
 run-make/unstable-flag-required/Makefile
-run-make/wasm-exceptions-nostd/Makefile
 run-make/x86_64-fortanix-unknown-sgx-lvi/Makefile

tests/run-make/wasm-exceptions-nostd/rmake.rs

@@ -0,0 +1,18 @@
+//@ only-wasm32-bare
+
+use std::path::Path;
+
+use run_make_support::{cmd, env_var, rustc};
+
+fn main() {
+    // Add a few command line args to make exceptions work
+    rustc()
+        .input(Path::new("src").join("lib.rs"))
+        .target("wasm32-unknown-unknown")
+        .panic("unwind")
+        .arg("-Cllvm-args=-wasm-enable-eh")
+        .arg("-Ctarget-feature=+exception-handling")
+        .run();
+
+    cmd(&env_var("NODE")).arg("verify.mjs").arg("lib.wasm").run();
+}

tests/run-make/wasm-exceptions-nostd/src/panicking.rs

@@ -17,8 +17,8 @@ fn panic_handler(info: &core::panic::PanicInfo<'_>) -> ! {
     use alloc::boxed::Box;
     use alloc::string::ToString;
 
-    let msg = info.message().map(|msg| msg.to_string()).unwrap_or("(no message)".to_string());
-    let exception = Box::new(msg.to_string());
+    let msg = info.message().to_string();
+    let exception = Box::new(msg);
     unsafe {
         let exception_raw = Box::into_raw(exception);
         wasm_throw(exception_raw as *mut u8);