This ensures:
1. The xorshift state is initialized during interp.
2. The xorshift state gets initialized to a real random number on
hardware that supports it at runtime.
This fixes a big binary size regression from the previous commit. It's
still not perfect: most programs increase binary size by a few bytes.
But it's not nearly as bad as before.
This function is needed for Go 1.22, and is used from various packages
like math/rand.
When there is no random number generator available, it falls back to a
static sequence of numbers. I think this is fine, because as far as I
can see it is only used for non-cryptographic needs.
This function is used by the hash/maphash package.
Unfortunately, I couldn't get the hash/maphash package to pass tests
because it's too slow. I think it hits the quadratic complexity of the
current map implementation.
Ayke van Laethem
Damian Gryski