Split out Rust BPF no-std stuff (#4968)

sdk/bpf/rust/rust-no-std/src/panic.rs

@@ -0,0 +1,31 @@
+//! @brief Solana Rust-based BPF program panic handling
+
+use core::panic::PanicInfo;
+use core::ptr;
+
+#[panic_handler]
+fn panic(info: &PanicInfo) -> ! {
+    // Message is ignored for now to avoid incurring formatting program size overhead
+    match info.location() {
+        Some(location) => {
+            let mut file: [u8; 128] = [0; 128];
+            for (i, c) in location.file().as_bytes().iter().enumerate() {
+                if i > 127 {
+                    break;
+                }
+                file[i] = *c;
+            }
+            unsafe {
+                sol_panic_(
+                    file.as_ptr(),
+                    u64::from(location.line()),
+                    u64::from(location.column()),
+                );
+            }
+        }
+        None => unsafe { sol_panic_(ptr::null(), 0, 0) },
+    }
+}
+extern "C" {
+    pub fn sol_panic_(file: *const u8, line: u64, column: u64) -> !;
+}