Remove `DatabaseStatements#case_sensitive_equality_operator`. It has been deprecated already.
#type_cast - improve performance & readability
updating  options documentation for associations
removed unnecessary test case and improved test case for belongs_to having invalid  options
Merge pull request #13100 from akshay-vishnoi/f-refactor

#type_cast - improve performance & readability
Merge pull request #13099 from kamipo/remove_case_sensitive_equality_operator

Remove `DatabaseStatements#case_sensitive_equality_operator`. It has been deprecated already.
Merge pull request #13095 from kuldeepaggarwal/test-case-updation

removed unnecessary test case