Add DWARF debug info support for C++11 inline namespaces.
This implements the DWARF 5 DW_AT_export_symbols feature:
http://dwarfstd.org/ShowIssue.php?issue=141212.1

<rdar://problem/18616046>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@285959 91177308-0d34-0410-b5e6-96231b3b80d8
16 files changed