Provide a panic handler

src/main.rs

@@ -1,3 +1,11 @@
 #![no_std]
 
+use core::panic::PanicInfo;
+
 fn main() {}
+
+/// This function is called on panic.
+#[panic_handler]
+fn panic(_info: &PanicInfo) -> ! {
+    loop {}
+}