[SPARK-4008] Fix "kryo with fold" in KryoSerializerSuite

`zeroValue` will be serialized by `spark.closure.serializer` but `spark.closure.serializer` only supports the default Java serializer. So it must not be `ClassWithoutNoArgConstructor`, which can not be serialized by the Java serializer.

This PR changed `zeroValue` to null and updated the test to make it work correctly.

Author: zsxwing <zsxwing@gmail.com>

Closes #2856 from zsxwing/SPARK-4008 and squashes the following commits:

51da655 [zsxwing] [SPARK-4008] Fix "kryo with fold" in KryoSerializerSuite
[SPARK-3904] [SQL] add constant objectinspector support for udfs

In HQL, we convert all of the data type into normal `ObjectInspector`s for UDFs, most of cases it works, however, some of the UDF actually requires its children `ObjectInspector` to be the `ConstantObjectInspector`, which will cause exception.
e.g.
select named_struct("x", "str") from src limit 1;

I updated the method `wrap` by adding the one more parameter `ObjectInspector`(to describe what it expects to wrap to, for example: java.lang.Integer or IntWritable).

As well as the `unwrap` method by providing the input `ObjectInspector`.

Author: Cheng Hao <hao.cheng@intel.com>

Closes #2762 from chenghao-intel/udf_coi and squashes the following commits:

bcacfd7 [Cheng Hao] Shim for both Hive 0.12 & 0.13.1
2416e5d [Cheng Hao] revert to hive 0.12
5793c01 [Cheng Hao] add space before while
4e56e1b [Cheng Hao] style issue
683d3fd [Cheng Hao] Add golden files
fe591e4 [Cheng Hao] update HiveGenericUdf for set the ObjectInspector while constructing the DeferredObject
f6740fe [Cheng Hao] Support Constant ObjectInspector for Map & List
8814c3a [Cheng Hao] Passing ContantObjectInspector(when necessary) for UDF initializing
[SPARK-4133] [SQL] [PySpark] type conversionfor python udf

Call Python UDF on ArrayType/MapType/PrimitiveType, the returnType can also be ArrayType/MapType/PrimitiveType.

For StructType, it will act as tuple (without attributes). If returnType is StructType, it also should be tuple.

Author: Davies Liu <davies@databricks.com>

Closes #2973 from davies/udf_array and squashes the following commits:

306956e [Davies Liu] Merge branch 'master' of github.com:apache/spark into udf_array
2c00e43 [Davies Liu] fix merge
11395fa [Davies Liu] Merge branch 'master' of github.com:apache/spark into udf_array
9df50a2 [Davies Liu] address comments
79afb4e [Davies Liu] type conversionfor python udf