aarch64: Translate rot{r,l} to ISLE (#3614)

This commit translates the `rotl` and `rotr` lowerings already existing
to ISLE. The port was relatively straightforward with the biggest
changing being the instructions generated around i128 rotl/rotr
primarily due to register changes.

cranelift/codegen/src/isa/aarch64/inst/imms.rs

@@ -583,7 +583,7 @@ impl ImmLogic {
 }
 
 /// An immediate for shift instructions.
-#[derive(Clone, Debug)]
+#[derive(Copy, Clone, Debug)]
 pub struct ImmShift {
     /// 6-bit shift amount.
     pub imm: u8,