Remove constants that denotes no data and use NULL values instead

[pinepain]

class Message {
    const kNoLineNumberInfo = 0;
    const kNoColumnInfo = 0;
    const kNoScriptIdInfo = 0;
...

class UnboundScript {
    const kNoScriptId = 0;
...

As 0 value is ambiguous as vast majority users without strong v8 internals background would be surprised that 0 is not a zero line number, but no info available.

We can safely return/use null to explicitly denote that no info available.

Note, UnboundScript, StackFrame and ScriptOrigin are also affected with this issue, maybe some other too.