Create a few generic testing functions to allow any memory/string tests
to be created.
Add alignment tests for memcpy/memset/strcat/strcpy/strlen.
Add an overread test for memcpy/strcat/strcpy/strlen. This test attempts
to verify that the functions do not read past the end of their buffers
(src buffer in the case of src/dst functions).
Bug: 9797008
Change-Id: Ib3223ca1b99e729ae8229adc2d03f4dc3103d97c
