Recommitting r201351 and r201355 (reverted in r201351 and r201355)
We weren't emitting the an empty (header only) line table when the line
table was empty - this made the DWARF invalid (the compile unit would
point to the zero-size debug_lines section where there should've been an
empty line table but there was nothing at all). Fix that, and as a
consequence this works around/addresses PR18809.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@201380 91177308-0d34-0410-b5e6-96231b3b80d8
35d2f61510