Add tests for the above.
Add the fortify implementations of __stpcpy_chk and __stpncpy_chk.
Modify the strncpy test to cover more cases and use this template for
stpncpy.
Add all of the fortify test cases.
Bug: 13746695
Change-Id: I8c0f0d4991a878b8e8734fff12c8b73b07fdd344
