[Kaleidoscope] Make Chapter 2 use llvm::make_unique, rather than a helper.

This essentially reverts r251936, minimizing the difference between Chapter2
and Chapter 3, and making Chapter 2's code match the tutorial text.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@281945 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed