Don’t crash when we get an invalid .debug_aranges set, just ignore it. Also print out warning messages if LLDB_CONFIGURATION_DEBUG is defined.

<rdar://problem/16516343>

git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@205634 91177308-0d34-0410-b5e6-96231b3b80d8