swift234

[CMake] Include ICU for stubs

`stdlib/public/stubs` includes `unicode/ustring.h`,
`unicode/ucol.h`, `unicode/ucoleitr.h`, and `unicode/uiter.h`.

Also, `stubs` comes before `core` in the CMake configuration order.
As a result, ICU includes are not configured in time for `stubs`.
This causes an error when building Swift for Android.

This behavior was introduced in d227aeb. This commit reverts the
include order change.