elf.h: new elf header flag to mark 2008-NaN vs legacy-NaN on mips

see glibc commit 9c21573c02446b3d5cf6a34b67c8545e5be6a600
elf.h: add aarch64 relocations
sys/socket.h: add the SO_MAX_PACING_RATE SOL_SOCKET option

introduced in linux v3.13, 62748f32d501f5d3712a7c372bbb92abc7c62bc7
if_ether.h: new ethernet protocol type

for High-availability Seamless Redundancy (HSR) specified in IEC 62439-3
new in linux v3.13, f421436a591d34fa5279b54a96ac07d70250cc8d
in.h: new IP_MTU_DISCOVER mode IP_PMTUDISC_INTERFACE

introduced in linux v3.13, 482fc6094afad572a4ea1fd722e7b11ca72022a0
to mitigate dns cache poisoning via fragmentation