testLeakingPrototypesAcrossContexts added in r146682 doesn't compile on Win and fails on Mac
https://bugs.webkit.org/show_bug.cgi?id=113125

Reviewed by Mark Hahnenberg

Remove the test added in r146682 as it's now failing on Mac.
This is the test that was causing a compilation failure on Windows.

* API/tests/testapi.c:
(main):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@146711 268f45cc-cd09-0410-ab3c-d52691b4dbfc