Add __rust_allocate_zeroed to work with newest nightly

alloc_kernel/src/lib.rs

@@ -4,6 +4,7 @@
 #![allocator]
 #![no_std]
 
+use core::ptr;
 use spin::Mutex;
 use linked_list_allocator::Heap;
 
@@ -25,6 +26,15 @@ pub extern fn __rust_allocate(size: usize, align: usize) -> *mut u8 {
     }
 }
 
+#[no_mangle]
+pub extern fn __rust_allocate_zeroed(size: usize, align: usize) -> *mut u8 {
+    let ptr = __rust_allocate(size, align);
+    unsafe {
+        ptr::write_bytes(ptr, 0, size);
+    }
+    ptr
+}
+
 #[no_mangle]
 pub extern fn __rust_deallocate(ptr: *mut u8, size: usize, align: usize) {
     if let Some(ref mut heap) = *HEAP.lock() {