Merge pull request from GHSA-hpqh-2wqx-7qp5

Fix spillslot reload of narrow values: zero-extend, don't sign-extend. Release v0.74.0 as security-patch release.

cranelift/codegen/src/isa/x64/inst/args.rs

@@ -1038,6 +1038,7 @@ impl fmt::Display for Avx512Opcode {
 /// This defines the ways a value can be extended: either signed- or zero-extension, or none for
 /// types that are not extended. Contrast with [ExtMode], which defines the widths from and to which
 /// values can be extended.
+#[allow(dead_code)]
 #[derive(Clone, PartialEq)]
 pub enum ExtKind {
     None,