message: [XLA] Fix HLO graph dumper not to assume that instruction names start with "%".
  HLO graph dumper needs to be aware that we've gotten rid of the "%"
  prefix in HLO names so it doesn't print e.g.
  reduce
  reduce.42
  Subcomputation: add
  ...
  but instead simply prints
  reduce.42
  Subcomputation: add
  ...
diff: @@ -784,7 +784,7 @@ string HloDotDumper::GetInstructionNodeInlinedOperands(
  // Otherwise, print e.g. "%constant.42 (s32[100])".
  string constant_name;
  - if (tensorflow::StringPiece(constant->name()).starts_with("%constant")) {
  + if (tensorflow::StringPiece(constant->name()).starts_with("constant")) {
  constant_name = constant->name();
  } else {
  constant_name = StrCat("constant ", constant->name());
  @@ -1000,7 +1000,7 @@ string HloDotDumper::GetInstructionNodeLabel(const HloInstruction* instr) {
  // The HLO instruction name contains usually the opcode, e.g. "%add.42" is
  // an add instruction. In this case we render just the name.
  if (tensorflow::StringPiece(instr->name())
  - .starts_with(StrCat("%", HloOpcodeString(instr->opcode())))) {
  + .starts_with(HloOpcodeString(instr->opcode()))) {
  return Printf("<b>%s</b>", HtmlLikeStringSanitize(instr->name()));
  }
  string extended_opcode =
  