Sorting was a bit of a mess; we had sort functions doing in-place
mutation /and/ returing the value, and people were confused by the
asymmetry of Array's sort() method with other higher-level methods.
Fixes <rdar://problem/17185815> sort([]T, f) mutates the original array
<rdar://problem/17225190> The Array.sort() method should return a sorted array
Swift SVN r18922
tuples and structs that are passed to a function by value.
<rdar://problem/15928331> Need to support DW_OP_piece for multi-Value variables/arguments
<rdar://problem/16599747> Variables not displayed at all in SwiftDemo02b_Closure (back again)
Swift SVN r17923
