[DWARFv5] Emit file 0 to the line table.

DWARF v5 specifies that the root file (also given in the DW_AT_name
attribute of the compilation unit DIE) should be emitted explicitly to
the line table's list of files.  This makes the line table more
independent of the .debug_info section.

Differential Revision: https://reviews.llvm.org/D44054

llvm-svn: 326758
diff --git a/llvm/test/MC/ARM/dwarf-asm-multiple-sections.s b/llvm/test/MC/ARM/dwarf-asm-multiple-sections.s
index 4c099ac..cff8f00 100644
--- a/llvm/test/MC/ARM/dwarf-asm-multiple-sections.s
+++ b/llvm/test/MC/ARM/dwarf-asm-multiple-sections.s
@@ -54,9 +54,9 @@
 // DWARF-DL: .debug_line contents:
 // DWARF-DL: version: [[DWVER]]
 // DWARF-DL-5:    address_size: 4
-// DWARF-DL-5:    include_directories[  0] = ""
+// DWARF-DL-5:    include_directories[  0] = "/tmp"
 // DWARF-DL:      file_names[  [[DWFILE]]]:
-// DWARF-DL:      name: "<stdin>"
+// DWARF-DL:      name: "{{(<stdin>|-)}}"
 // DWARF-DL:      0x0000000000000000     17      0      1   0   0  is_stmt
 // DWARF-DL-NEXT: 0x0000000000000004     17      0      1   0   0  is_stmt end_sequence
 // DWARF-DL-NEXT: 0x0000000000000000     21      0      1   0   0  is_stmt