In profiler, i need to access original rule that contained pred. happy to find another way to provide it. I do this:

```
		if ( semctx instanceof SemanticContext.PrecedencePredicate ) {
			Rule rule = g.getRule(((SemanticContext.PrecedencePredicate)semctx).ruleIndex);
			int precedence = ((SemanticContext.PrecedencePredicate)semctx).precedence;
			// precedence = n - originalAlt + 1, So:
			int originalAlt = rule.getOriginalNumberOfAlts()-precedence+1;
			alt = originalAlt;
		}
```