Ada has not stand still, the latest standard revision is from 2012.
http://www.ada2012.org/
It has all the modern goodies in it, OOP, interfaces, contracts alongside type safety.
Then if you really care about high integrity systems, there is its brother SPARK, which is a hardened version of Ada, the latest revision being from 2014.
http://www.spark-2014.org/
Regarding calling memcpy() and memmove(), the compilers should be able to produce the right kind of code.
Now if you really mean the C functions, the aliasing declaration should be part of declaration.
Not sure what is the current state of Ada's POSIX specification.