[DWARF] Emit a split line table only if there are split type units.

A .debug_info.dwo section doesn't use the .debug_line.dwo section.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@326395 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed