message: [DWARF] Fix Swift build after r361849
  r361849 removed the one-argument constructor to DWARFExpression. In this
  case, we can just switch to the default constructor, since the
  constructed object is being used with GetDIENamesAndRanges, which has
  been updated to fill in the CU itself.
diff: @@ -298,7 +298,7 @@ Function *DWARFASTParserSwift::ParseFunctionFromDWARF(
  int call_file = 0;
  int call_line = 0;
  int call_column = 0;
  - DWARFExpression frame_base(die.GetCU());
  + DWARFExpression frame_base;
  if (die.Tag() != DW_TAG_subprogram)
  return NULL;
  