Modify the stack set up when ARM7/9 tasks are created to ensure the assert() calls...

Modify the stack set up when ARM7/9 tasks are created to ensure the assert() calls in xTaskCreate() don't fail.  In this case, the assert that would fail is actually redundant anyway, but should not be removed as it might not be redundant in all ports.

git-svn-id: https://svn.code.sf.net/p/freertos/code/trunk@1571 1d2547de-c912-0410-9cb9-b8ca96c0e9e2