gen-arm: s/simd_reinterpret/transmute_unchecked

`simd_reinterpret` was expected to be used when it was added as
`transmute_unchecked` requires `Sized`, but scalable vectors are now
`Sized` so `transmute_unchecked` can be used and `simd_reinterpret` was
not added in rust-lang#143924.

Author: davidtwco

library/stdarch/crates/stdarch-gen-arm/src/typekinds.rs

@@ -289,9 +289,9 @@ impl TypeKind {
                     (
                         BaseType::Sized(Float | Int | UInt, _),
                         BaseType::Sized(Float | Int | UInt, _),
-                    ) => Some(FnCall::new_expression(
+                    ) => Some(FnCall::new_unsafe_expression(
                         // Conversions between float and (u)int, or where the lane size changes.
-                        "simd_reinterpret".parse().unwrap(),
+                        "transmute_unchecked".parse().unwrap(),
                         vec![expr.into()],
                     )),
                     _ => None,