message: Fix "default argument for lambda parameter" (-Wpedantic) warning
diff: @@ -579,7 +579,7 @@ public:
  s.Printf("\n");
  }
  auto DumpTextStream = [&](MinidumpStreamType stream_type,
  - llvm::StringRef label = llvm::StringRef()) -> void {
  + llvm::StringRef label) -> void {
  auto bytes = minidump.GetStream(stream_type);
  if (!bytes.empty()) {
  if (label.empty())
  @@ -588,7 +588,7 @@ public:
  }
  };
  auto DumpBinaryStream = [&](MinidumpStreamType stream_type,
  - llvm::StringRef label = llvm::StringRef()) -> void {
  + llvm::StringRef label) -> void {
  auto bytes = minidump.GetStream(stream_type);
  if (!bytes.empty()) {
  if (label.empty())
  