Fix article for generator name

Use 'some' instead of 'a/an'.
Merge pull request #9185 from tricknotes/fix-article-for-generator-name

Fix article for generator name
Change behaviour with empty hash in where clause
Merge pull request #9220 from robertomiranda/where-with-empty-hash

Active Record: Change behaviour with empty hash in where clause
Change behaviour with empty array in where clause
Merge pull request #9216 from robertomiranda/where-with-empty-array

Activer Record:  Change behaviour with empty array in where clause
Improve changelog entries in AR

Describe better the changes related to raising errors with empty
array/hash values in where clauses.

[ci skip]