fix(executor): limit should exit early when offset and limit are both 0

[xxchan]

Fix #264

The issue can be reproduced using memory engine like this: (Btw, the sqlogictest fails for both disk & memory engines)

> create table t(x int);insert into t values (0);insert into t values (0);
> select * from t limit 0;

The execution process is

processed 0, cardinality 1, offsef 0, limit 0
processed 1, cardinality 1, offsef 0, limit 0 # boom

Because when offset=limit=0, start=end=0, and thus it will continue.

risinglight/src/executor/limit.rs

Lines 27 to 32 in fea5e0b

	let start = processed.max(self.offset) - processed;
	let end = (processed + cardinality).min(self.offset + self.limit) - processed;
	processed += cardinality;
	if start >= end {
	continue;
	}

[skyzh]

Thanks!