Fix an integer overflow bug.

This is the update to add the new unit test to the Android makefile,
test script, and update jemalloc_internal.h to match the .in version.

Bug: 21633176
(cherry picked from commit 35d78ee733903e8706a4b7c870252f2a501019a5)

Change-Id: I8d9252bfd56a2f28f908f53d2132bb6fef3c538f
3 files changed