StringBuilderSubstringLength 2476 src/runtime.cc     if (StringBuilderSubstringLength::is_valid(length) &&
StringBuilderSubstringLength 2478 src/runtime.cc       int encoded_slice = StringBuilderSubstringLength::encode(length) |
StringBuilderSubstringLength 6871 src/runtime.cc         len = StringBuilderSubstringLength::decode(encoded_slice);
StringBuilderSubstringLength 6940 src/runtime.cc         len = StringBuilderSubstringLength::decode(smi_value);