[D-runtime] [D-Programming-Language/druntime] 8788a2: add makefile for Win64

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/D-Programming-Language/druntime
  Commit: 8788a2b1c29dd9d2d401ef74d6dc1758fcbda563
      https://github.com/D-Programming-Language/druntime/commit/8788a2b1c29dd9d2d401ef74d6dc1758fcbda563
  Author: Walter Bright <walter at walterbright.com>
  Date:   2012-09-08 (Sat, 08 Sep 2012)

  Changed paths:
    A win64.mak

  Log Message:
  -----------
  add makefile for Win64