am b5239ed1: libc: allow usage of time64.h from cpp code

Merge commit 'b5239ed16aeba648f1c9bcb7a4887b8a41670326' into eclair-mr2-plus-aosp

* commit 'b5239ed16aeba648f1c9bcb7a4887b8a41670326':
  libc: allow usage of time64.h from cpp code