fix ForInArrayAnalyzer where it would break when array was not in scope

If array in the `for` declaration was declared outside the method scope
the symbol would not be found and an null reference exception would
be thrown. See associated test to an example of the now fixed case.
Merge pull request #63 from giggio/FixArrayInForEachAnalyzer

Fix ForInArrayAnalyzer where it would break when array was not in scope