Add an Xcode project to build 64-bit UnixPkg. Currently crashes in PeiCore().

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@10651 6f19259b-4bc3-4df7-8a09-765794883524

UnixPkg/Xcode/xcode_project64/XcodeBuild.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+#
+# External makefile Xcode project project uses this script to build and clean from the Xcode GUI
+#
+
+# force exit on error
+set -e
+
+#
+# Source the workspace and set up the environment varaibles we need
+#
+cd ../..
+echo `pwd`
+./build64.sh