swift234

allow 'var' and 'let' to appear in patterns (not just matching patterns).
This allows them to appear in argument lists of functions, enabling behavior
like this:

func test_arguments(a : Int, var b : Int, let c : Int) {
  a = 1  // ok (for now).
  b = 2  // ok.
  c = 3  // expected-error {{cannot assign to the result of this expression}}
}



Swift SVN r11746