Rename struct to class per #651 (#765)

executable_semantics/testdata/class1.carbon

@@ -0,0 +1,13 @@
+// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
+// Exceptions. See /LICENSE for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+class Point {
+  var x: i32;
+  var y: i32;
+}
+
+fn main() -> i32 {
+  var p: auto = Point(.x = 1, .y = 2);
+  return p.y - p.x - 1;
+}