[SPARK-5324][SQL] Results of describe can't be queried

Make below code works.
```
sql("DESCRIBE test").registerTempTable("describeTest")
sql("SELECT * FROM describeTest").collect()
```

Author: OopsOutOfMemory <victorshengli@126.com>
Author: Sheng, Li <OopsOutOfMemory@users.noreply.github.com>

Closes #4249 from OopsOutOfMemory/desc_query and squashes the following commits:

6fee13d [OopsOutOfMemory] up-to-date
e71430a [Sheng, Li] Update HiveOperatorQueryableSuite.scala
3ba1058 [OopsOutOfMemory] change to default argument
aac7226 [OopsOutOfMemory] Merge branch 'master' into desc_query
68eb6dd [OopsOutOfMemory] Merge branch 'desc_query' of github.com:OopsOutOfMemory/spark into desc_query
354ad71 [OopsOutOfMemory] query describe command
d541a35 [OopsOutOfMemory] refine test suite
e1da481 [OopsOutOfMemory] refine test suite
a780539 [OopsOutOfMemory] Merge branch 'desc_query' of github.com:OopsOutOfMemory/spark into desc_query
0015f82 [OopsOutOfMemory] code style
dd0aaef [OopsOutOfMemory] code style
c7d606d [OopsOutOfMemory] rename test suite
75f2342 [OopsOutOfMemory] refine code and test suite
f942c9b [OopsOutOfMemory] initial
11559ae [OopsOutOfMemory] code style
c5fdecf [OopsOutOfMemory] code style
aeaea5f [OopsOutOfMemory] rename test suite
ac2c3bb [OopsOutOfMemory] refine code and test suite
544573e [OopsOutOfMemory] initial