Adds an implementation of xoshiro128++ as a pseudo random number
generator from https://prng.di.unimi.it/ that operates on 32bit words.
The algorithm postfix signifies the main operation in the generation
function. Therefore xoshiro++ is chosen over xoshiro** as we would
prefer to do 2 additions isntead of 2 multiplications on embedded
hardware. The quality of the generators appears to be the same in all
other respects.
xoshiro+ is not chosen despite being faster as it generates random
floating-point values, not general purpose random values (The lower 4
bits are linear).
Signed-off-by: Jordan Yates <jordan.yates@data61.csiro.au>
Jordan Yates