fa4b52bd16 fuzz: refactor memcpy to std::ranges::copy to work around ubsan warn (MarcoFalke)
Pull request description:
Using std::ranges::copy from the C++ standard library has a few benefits here:
* It has the additional benefit of being a bit more type safe and document the byte cast explicitly.
* The compiler will likely optimize it to the same asm, but performance doesn't really matter here anyway.
* It has defined semantics for empty source ranges.
Fixes https://github.com/bitcoin/bitcoin/issues/33643
ACKs for top commit:
marcofleon:
tACK fa4b52bd16
dergoegge:
utACK fa4b52bd16
Tree-SHA512: 04fcf096e3cfc526e996c9313ec6e0a4d12c382fa19cb846b51564d33de2f0ef78a588fc6a936da0c76ca8bc9d9db4a824c36d99413db4f538a98239864d48f0