Add support for a CU to output a set of ranges for the CU. This is useful
when you want to have the full list of addresses for a particular CU or
when you have multiple modules linked together and can't depend upon the
ordering of a single CU for begin/end ranges.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@197776 91177308-0d34-0410-b5e6-96231b3b80d8