Issue 3223: Second phase of migration to Rust Edition

Reformat via `cargo fmt`

src/machine/stack.rs

@@ -175,15 +175,17 @@ impl Stack {
     }
 
     #[inline(always)]
-    unsafe fn alloc(&mut self, frame_size: usize) -> Result<NonNull<u8>, AllocError> { unsafe {
-        loop {
-            let ptr = self.buf.alloc(frame_size);
-            if let Some(ptr) = NonNull::new(ptr) {
-                return Ok(ptr);
+    unsafe fn alloc(&mut self, frame_size: usize) -> Result<NonNull<u8>, AllocError> {
+        unsafe {
+            loop {
+                let ptr = self.buf.alloc(frame_size);
+                if let Some(ptr) = NonNull::new(ptr) {
+                    return Ok(ptr);
+                }
+                self.buf.grow()?;
             }
-            self.buf.grow()?;
         }
-    }}
+    }
 
     pub(crate) fn allocate_and_frame(&mut self, num_cells: usize) -> Result<usize, AllocError> {
         let frame_size = AndFrame::size_of(num_cells);