Remove implementation of unchecked_serialize

Since we're checking `serializable?` in the new `HomogeneousIn`
`serialize` will no longer raise an exception. We implemented
`unchecked_serialize` to avoid raising in these cases, but with some of
our refactoring we no longer need it.

I discovered this while trying to fix a query in our application that
was not properly serializing binary columns. I discovered that in at
least 2 of our active model types we were not calling the correct
serialization. Since `serialize` wasn't aliased to `unchecked_serialize`
in `ActiveModel::Type::Binary` and `ActiveModel::Type::Boolean` (I
didn't check others but pretty sure all the AM Types are broken) the SQL
was being treated as a `String` and not the correct type.

This caused Rails to incorrectly query by string values. This is
problematic for columns storing binary data like our emoji columns at
GitHub. The test added here is an example of how the Binary type was
broken previously. The SQL should be using the hex values, not the
string value of "🥦" or other emoji.

We still have the problem `unchecked_serialize` was supposed to fix -
that `serialize` shouldn't validate data, just convert it. We'll be
fixing that in a followup PR so for now we should use `serialize` so we
know all the values are going through the right serialization for their
SQL.

activemodel/lib/active_model/type/helpers/numeric.rb

@@ -7,7 +7,6 @@ module ActiveModel
         def serialize(value)
           cast(value)
         end
-        alias :unchecked_serialize :serialize
 
         def cast(value)
           # Checks whether the value is numeric. Spaceship operator

activemodel/lib/active_model/type/value.rb

@@ -53,7 +53,6 @@ module ActiveModel
       def serialize(value)
         value
       end
-      alias :unchecked_serialize :serialize
 
       # Type casts a value for schema dumping. This method is private, as we are
       # hoping to remove it entirely.

activerecord/lib/active_record/enum.rb

@@ -146,7 +146,6 @@ module ActiveRecord
       def serialize(value)
         mapping.fetch(value, value)
       end
-      alias :unchecked_serialize :serialize
 
       def assert_valid_value(value)
         unless serializable?(value)

activerecord/lib/arel/nodes/homogeneous_in.rb

@@ -44,7 +44,7 @@ module Arel # :nodoc: all
         type = attribute.type_caster
 
         casted_values = values.map do |raw_value|
-          type.unchecked_serialize(raw_value) if type.serializable?(raw_value)
+          type.serialize(raw_value) if type.serializable?(raw_value)
         end
 
         casted_values.compact!

activerecord/lib/arel/visitors/to_sql.rb

@@ -327,9 +327,9 @@ module Arel # :nodoc: all
           collector << quote_table_name(o.table_name) << "." << quote_column_name(o.column_name)
 
           if o.type == :in
-            collector << "IN ("
+            collector << " IN ("
           else
-            collector << "NOT IN ("
+            collector << " NOT IN ("
           end
 
           values = o.casted_values.map { |v| @connection.quote(v) }

activerecord/test/cases/relation/where_test.rb

@@ -366,6 +366,12 @@ module ActiveRecord
       assert_equal 0, count
     end
 
+    def test_where_with_emoji_for_binary_column
+      Binary.create!(data: "🥦")
+      assert Binary.where(data: ["🥦", "🍦"]).to_sql.include?("f09fa5a6")
+      assert Binary.where(data: ["🥦", "🍦"]).to_sql.include?("f09f8da6")
+    end
+
     def test_where_on_association_with_custom_primary_key
       author = authors(:david)
       essay = Essay.where(writer: author).first