Refactor schema creation to extract new_foreign_key_definition

Follow rails/rails@ecd4c84.

Author: koic

lib/active_record/connection_adapters/oracle_enhanced/schema_creation.rb

@@ -21,7 +21,7 @@ def visit_TableDefinition(o)
             statements << accept(o.primary_keys) if o.primary_keys
 
             if supports_foreign_keys?
-              statements.concat(o.foreign_keys.map { |to_table, options| foreign_key_in_create(o.name, to_table, options) })
+              statements.concat(o.foreign_keys.map { |fk| accept fk })
             end
 
             create_sql << "(#{statements.join(', ')})" if statements.present?