Apply upstream commit 943a6621866e9d6e654f5cfe1494378c1fb8957a.

Author: Paul Eggert <eggert@cs.ucla.edu>
Date:   Thu Aug 22 12:47:51 2013 -0700

    * localtime.c: Fix another integer overflow bug in mktime.

    (time2sub): Avoid undefined behavior on time_t overflow.
    Reported by Elliott Hughes in
    <http://mm.icann.org/pipermail/tz/2013-August/019580.html>.

Bug: 10310929
Change-Id: I3bf26f1f91371552e0a3828457d27e22af55acb2

Conflicts:
	libc/Android.mk
	libc/tzcode/localtime.c