BUILD FIX: testapi should link to Foundation, not CoreFoundation

* JavaScriptCore.xcodeproj/project.pbxproj: Change testapi to
link to Foundation.framework instead of CoreFoundation.framework
since it uses NS types.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@144521 268f45cc-cd09-0410-ab3c-d52691b4dbfc