CL/aarch64: implement the wasm SIMD i32x4.dot_i16x8_s instruction

This patch implements, for aarch64, the following wasm SIMD extensions

  i32x4.dot_i16x8_s instruction
  https://github.com/WebAssembly/simd/pull/127

It also updates dependencies as follows, in order that the new instruction can
be parsed, decoded, etc:

  wat          to  1.0.27
  wast         to  26.0.1
  wasmparser   to  0.65.0
  wasmprinter  to  0.2.12

The changes are straightforward:

* new CLIF instruction `widening_pairwise_dot_product_s`

* translation from wasm into `widening_pairwise_dot_product_s`

* new AArch64 instructions `smull`, `smull2` (part of the `VecRRR` group)

* translation from `widening_pairwise_dot_product_s` to `smull ; smull2 ; addv`

There is no testcase in this commit, because that is a separate repo.  The
implementation has been tested, nevertheless.

cranelift/wasm/src/code_translator.rs

@@ -1782,9 +1782,18 @@ pub fn translate_operator<FE: FuncEnvironment + ?Sized>(
             state.push1(builder.ins().nearest(arg));
         }
 
+        Operator::I32x4DotI16x8S => {
+            let (a, b) = pop2_with_bitcast(state, I16X8, builder);
+            state.push1(builder.ins().widening_pairwise_dot_product_s(a, b));
+        }
+
         Operator::ReturnCall { .. } | Operator::ReturnCallIndirect { .. } => {
             return Err(wasm_unsupported!("proposed tail-call operator {:?}", op));
         }
+
+        Operator::V128Load32Zero { .. } | Operator::V128Load64Zero { .. } => {
+            return Err(wasm_unsupported!("proposed SIMD operator {:?}", op));
+        }
     };
     Ok(())
 }