DataLayout now returns a const ref to its member string representation

There was no particular reason to return by value in the first place.

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@240826 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed