Providing migration guide from Avx to Neon for Golang

[yingfeng]

Using SIMD in Golang is pretty difficult, since it requires to be translated into Golang assembling(Plan9 format), therefore, such tools as avo is very useful to alleviate the burden from write assembling manually. However, avo could only support x86 SIMD, could similar works be done on such project such that using Neon in Golang could be convenient enough ? Thank you~