Problem:- If we create table field with dynamic default value then that
 field always gets NULL value.

Analyze:- This is because in fill_record we simple continue at Invisible
 column because we though that share->default_values(default value is
 always copied into table->record[0] before insert) will have a default
 value for them(which is true for constant defaults , but not for dynamic
 defaults).

Solution:- We simple set all_fields_have_value to null , and this will
make call to update_default_fields (in the case of dynamic default), And
default expr will be evaluted and value will be set in field.