[agx - Rust] Implement Add for RectInsets

docs/todo.md

@@ -320,4 +320,6 @@ Auto install LLD link? Or llvm with brew? Need lld-link for the UEFI build
 // different on each OS), we could have an enum to model the possible font options, with an escape hatch 
 // 'get from this path' variant, which could perhaps hold different values depending on the OS. 
 
-Better errors when you try to use (ex.) printf before the VMM has initialized
+Better errors when you try to use (ex.) printf before the VMM has initialized
+
+Perhaps the VM allocator could inspect the call stack to ensure no one is trying to call it from the PMM? Could only be enabled on debug builds?

rust_programs/agx_definitions/src/lib.rs

@@ -464,6 +464,20 @@ impl RectInsets {
     }
 }
 
+impl Add for RectInsets {
+    type Output = RectInsets;
+
+    fn add(self, rhs: RectInsets) -> Self::Output {
+        // TODO(PT): The side order here should match the constructor passed to inset_by()...
+        RectInsets::new(
+            self.left + rhs.left,
+            self.top + rhs.top,
+            self.right + rhs.right,
+            self.bottom + rhs.bottom,
+        )
+    }
+}
+
 #[derive(Debug, Clone, Copy, PartialEq, Ord, PartialOrd, Eq)]
 pub struct Rect {
     pub origin: Point,