Inform Arel that we don't need type casting in tests

Part of the larger refactoring to remove type casting from Arel. We can
inform it that we already have the right type by wrapping the value in
an `Arel::Nodes::Quoted`. This commit can be reverted when we have
removed type casting from Arel in Rail 5.1

activerecord/test/cases/relation_test.rb

@@ -64,20 +64,21 @@ def test_empty_where_values_hash
 
     def test_has_values
       relation = Relation.new(Post, Post.arel_table, Post.predicate_builder)
-      relation.where! relation.table[:id].eq(10)
+      relation.where! relation.table[:id].eq(Arel::Nodes::Quoted.new(10))
       assert_equal({:id => 10}, relation.where_values_hash)
     end
 
     def test_values_wrong_table
       relation = Relation.new(Post, Post.arel_table, Post.predicate_builder)
-      relation.where! Comment.arel_table[:id].eq(10)
+      relation.where! Comment.arel_table[:id].eq(Arel::Nodes::Quoted.new(10))
       assert_equal({}, relation.where_values_hash)
     end
 
     def test_tree_is_not_traversed
       relation = Relation.new(Post, Post.arel_table, Post.predicate_builder)
-      left     = relation.table[:id].eq(10)
-      right    = relation.table[:id].eq(10)
+      # FIXME: Remove the Arel::Nodes::Quoted in Rails 5.1
+      left     = relation.table[:id].eq(Arel::Nodes::Quoted.new(10))
+      right    = relation.table[:id].eq(Arel::Nodes::Quoted.new(10))
       combine  = left.and right
       relation.where! combine
       assert_equal({}, relation.where_values_hash)
@@ -102,7 +103,8 @@ def test_create_with_value
 
     def test_create_with_value_with_wheres
       relation = Relation.new(Post, Post.arel_table, Post.predicate_builder)
-      relation.where! relation.table[:id].eq(10)
+      # FIXME: Remove the Arel::Nodes::Quoted in Rails 5.1
+      relation.where! relation.table[:id].eq(Arel::Nodes::Quoted.new(10))
       relation.create_with_value = {:hello => 'world'}
       assert_equal({:hello => 'world', :id => 10}, relation.scope_for_create)
     end
@@ -112,7 +114,8 @@ def test_scope_for_create_is_cached
       relation = Relation.new(Post, Post.arel_table, Post.predicate_builder)
       assert_equal({}, relation.scope_for_create)
 
-      relation.where! relation.table[:id].eq(10)
+      # FIXME: Remove the Arel::Nodes::Quoted in Rails 5.1
+      relation.where! relation.table[:id].eq(Arel::Nodes::Quoted.new(10))
       assert_equal({}, relation.scope_for_create)
 
       relation.create_with_value = {:hello => 'world'}