test.wat - external/github.com/WebAssembly/binaryen - Git at Google

 (module
   (type $s (struct (field (mut i32))))
   (func $a (param $ref (ref $s))
     (struct.set $s 0 (local.get $ref) (i32.const 5))
     (struct.set $s 0 (local.get $ref) (i32.const 4))
     (struct.set $s 0 (local.get $ref) (i32.const 4))
   )
 )
	(module
	(type $s (struct (field (mut i32))))
	(func $a (param $ref (ref $s))
	(struct.set $s 0 (local.get $ref) (i32.const 5))
	(struct.set $s 0 (local.get $ref) (i32.const 4))
	(struct.set $s 0 (local.get $ref) (i32.const 4))
	)
	)