desc: Sanity Check Fails, with r.table() expression inside a map (#453)
table_variable_name: tbl
tests:

  - cd: tbl.insert([{'a':1},{'a':2}])
    ot: partial({'inserted':2})

  - js: tbl.map(function(x) { return tbl; })
    py: tbl.map(lambda x: tbl)
    rb: tbl.map{ |x| tbl }
    ot: err("ReqlQueryLogicError", 'Expected type DATUM but found TABLE:', [0])

  - js: tbl.map(function(x) { return tbl.coerceTo('array'); }).count()
    py: tbl.map(lambda x: tbl.coerce_to('array')).count()
    rb: tbl.map{ |x| tbl.coerce_to('array') }.count
    ot: 2