swift234

[stdlib] Replace the old Array implementation

NewArray has landed!

All the groundwork for NSArray bridging has been laid, but there are
definitely a few details that still need to be handled (e.g. an implicit
conversion operator extension in the Foundation library).  There are
also many niceties we'll be able to add when Joe Pamer finishes his work
on same-type constraints.

Seven tests are XFAIL'd at Ted's direction:

<rdar://problem/16533351> [New Array] test/DebugInfo/linetable-cleanups.swift is broken

<rdar://problem/16533359> [New Array] Interactions with DynamicLookup
  Interpreter/SDK/objc_dynamic_lookup.swift
  Interpreter/SDK/objc_fast_enumeration.swift

<rdar://problem/16533367> [New Array] SILPasses tests are XFAIL'd
  SILPasses/dead_func.swift
  SILPasses/linker.swift
  SILPasses/spec_recursion.swift

<rdar://problem/16533371> [New Array] Reflection test runs forever
  stdlib/Reflection.swift

Swift SVN r15990