Use mingw64 target spelling.

Author: vadimcn

src/etc/get-snapshot.py

@@ -53,7 +53,7 @@ def unpack_snapshot(triple, dl_path):
   dl_path = sys.argv[2]
 else:
   # There are no 64-bit Windows snapshots yet, so we'll use 32-bit ones instead, for now
-  snap_triple = triple if triple != "x86_64-w64-mingw32" else "i686-pc-mingw32"
+  snap_triple = triple if triple != "x86_64-w64-mingw32" else "i686-w64-mingw32"
   snap = determine_curr_snapshot(snap_triple)
   dl = os.path.join(download_dir_base, snap)
   url = download_url_base + "/" + snap