Fix comment.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171832 91177308-0d34-0410-b5e6-96231b3b80d8
Remove the llvm-local DW_TAG_vector_type tag and add a test to
make sure that vector types do work.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171833 91177308-0d34-0410-b5e6-96231b3b80d8