swift234

[stdlib] Eager non-verbatim bridging

Trying to lazily compute bridge results and cache them isn't going to
work, because there's no place to efficiently invalidate the cache in
cases like this:

  func f(a: NSArray) {
    for i in 0...a.count {
      println(a.objectAtIndex(i)) // Fills up the cache
    }
  }

  var message = ["hello", "world"]
  f(message)
  message[0] = "goodbye, cruel" // need a cache invalidation or else
  f(message)                    // ...this prints "hello\nworld\n"

Since we need C performance for subscript assignment, we just can't
afford to do anything extra there.

Instead, when the element type isn't "Bridged Verbatim," just eagerly
convert it to an NSArray.

Swift SVN r17722