3351c91ed4 refactor: Make CScriptVisitor stateless (João Barbosa)
Pull request description:
`CScriptVisitor` was added in 1025440184 (#1357) and the visitor return type was never used. Now `CScriptVisitor` is stateless and `CScript` is the return type.
ACKs for top commit:
MarcoFalke:
ACK 3351c91ed4🏤
sipa:
utACK 3351c91ed4
Tree-SHA512: d158ad2ebe8ea4dc8cc090b943dd66fa5421a84f9443e16ab2d661df38e1a85de16ff13cbaa56924489d8d43cba25fa3cd8b6904bbbcbf356b886ffe8ffba19a