Update DataLayout/DescriptionString for ppc64le
Update DataLayout/DescriptionString for ppc64le

Similar LLVM change made in r203664

Testcase included.




git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@204613 91177308-0d34-0410-b5e6-96231b3b80d8