am 3a1bbee3: Add eventfd system call support

Merge commit '3a1bbee36b773862e88c6f1895b607c0cd81b499' into gingerbread-plus-aosp

* commit '3a1bbee36b773862e88c6f1895b607c0cd81b499':
  Add eventfd system call support

diff --cc libc/SYSCALLS.TXT
Simple merge

diff --cc libc/arch-arm/syscalls.mk
Simple merge

diff --cc libc/include/sys/linux-syscalls.h
Simple merge

diff --cc libc/include/sys/linux-unistd.h
Simple merge