foo(return)
    ^~~~~~ unexpected void value expression
foo(1, return)
       ^~~~~~ unexpected void value expression
foo(*return)
     ^~~~~~ unexpected void value expression
foo(**return)
      ^~~~~~ unexpected void value expression
foo(&return)
     ^~~~~~ unexpected void value expression
foo(return => 1)
    ^~~~~~ unexpected void value expression
foo(:a => return)
          ^~~~~~ unexpected void value expression
foo(a: return)
       ^~~~~~ unexpected void value expression

