Add tests for special case mappings

...-ins/String/prototype/toLocaleLowerCase/special_casing.js

...prototype/toLocaleLowerCase/special_casing_conditional.js

...-ins/String/prototype/toLocaleUpperCase/special_casing.js

.../built-ins/String/prototype/toLowerCase/special_casing.js

...tring/prototype/toLowerCase/special_casing_conditional.js

.../built-ins/String/prototype/toUpperCase/special_casing.js

.../String/prototype/toLocaleLowerCase/capital_I_with_dot.js

...tring/prototype/toLocaleLowerCase/special_casing_Azeri.js

.../prototype/toLocaleLowerCase/special_casing_Lithuanian.js

...ing/prototype/toLocaleLowerCase/special_casing_Turkish.js

...tring/prototype/toLocaleUpperCase/special_casing_Azeri.js

.../prototype/toLocaleUpperCase/special_casing_Lithuanian.js

...ing/prototype/toLocaleUpperCase/special_casing_Turkish.js