Revert removing a DiffTests regression

Author: chengluyu

shared/src/test/diff/codegen/Terms.mls

@@ -344,17 +344,11 @@ case A { a = 0 } of
 
 // With
 {} with {}
+:js
 rcd1 = { x = "a"; y = "b" }
 rcd2 = rcd1 with { x = 1; z = 2 }
 (rcd1.x, rcd1.y, rcd2.x, rcd2.y, rcd2.z)
-//│ res: anything
-//│    = {}
-//│ rcd1: {x: "a", y: "b"}
-//│     = { x: 'a', y: 'b' }
-//│ rcd2: {x: 1, y: "b", z: 2}
-//│     = { x: 1, y: 'b', z: 2 }
-//│ res: ("a", "b", 1, "b", 2,)
-//│    = [ 'a', 'b', 1, 'b', 2 ]
+//│ /!\ Parse error: Expected end-of-input:1:12, found ":js;rcd1 =" at l.347:1: :js
 
 class M: {mut x : int}
 //│ Defined class M