[Qt][Mac] Build fails after adding ICU support (r105997).

[Qt][Mac] Build fails after adding ICU support (r105997).
https://bugs.webkit.org/show_bug.cgi?id=77118

Source/JavaScriptCore:

Use Apple code path for unicode date formats on mac.

Reviewed by Tor Arne Vestbø.

* runtime/DatePrototype.cpp:
():

Source/WebCore:

Use SmareReplaceCF.cpp code path if platform Mac.

Reviewed by Tor Arne Vestbø.

* Target.pri:

Source/WTF:

Link to libicucore if platform Mac.

Reviewed by Tor Arne Vestbø.

* WTF.pri:

Tools:

Define WTF_USE_ICU_UNICODE if we are on mac.

Reviewed by Tor Arne Vestbø.

* qmake/mkspecs/features/features.prf:

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@106118 268f45cc-cd09-0410-ab3c-d52691b4dbfc