Mixed directory levels in test/intl402/

[ptomato]

In the test/intl402/ directory there is a mix of directory names that represent builtins reachable from the global object (e.g. Array/prototype/toLocaleString/, Date/prototype/) and names that represent builtins reachable from the Intl object (e.g. DateTimeFormat).

Specifically this means there are two directories with DateTimeFormat tests: test/intl402/DateTimeFormat/ and test/intl402/Intl/DateTimeFormat/.

The in-progress work on the README suggests that the names should be organized according to how they are reachable from the global object.