DI: Update and prune metadata examples

Update a couple of the examples of debug info metadata, and prune the
rest.  Point to the true reference implementation in the source.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219051 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed