Create a minimal bare-bones executable

src/main.rs

@@ -1,3 +1,9 @@
-fn main() {
+#![no_std]
-    println!("Hello, world!");
+#![no_main]
+
+use core::panic::PanicInfo;
+
+#[panic_handler]
+fn panic(_info: &PanicInfo) -> ! {
+    loop {}
 }