Fix encode, decode for load_zero (#391)

Author: ngzhian

interpreter/binary/decode.ml

@@ -411,6 +411,8 @@ let simd_prefix s =
   | 0xf9l -> i32x4_trunc_sat_f32x4_u
   | 0xfal -> f32x4_convert_i32x4_s
   | 0xfbl -> f32x4_convert_i32x4_u
+  | 0xfcl -> let a, o = memop s in v128_load32_zero a o
+  | 0xfdl -> let a, o = memop s in v128_load64_zero a o
   | n -> illegal s pos (I32.to_int_u n)
 
 let rec instr s =

interpreter/binary/encode.ml

@@ -220,6 +220,10 @@ let encode m =
         simd_op 0x09l; memop mo
       | SimdLoad ({ty= V128Type; sz = Some (Pack64, PackSplat); _} as mo) ->
         simd_op 0x0al; memop mo
+      | SimdLoad ({ty= V128Type; sz = Some (Pack32, PackZero); _} as mo) ->
+        simd_op 0xfcl; memop mo
+      | SimdLoad ({ty= V128Type; sz = Some (Pack64, PackZero); _} as mo) ->
+        simd_op 0xfdl; memop mo
 
       | Store ({ty = I32Type; sz = None; _} as mo) -> op 0x36; memop mo
       | Store ({ty = I64Type; sz = None; _} as mo) -> op 0x37; memop mo

interpreter/text/arrange.ml

@@ -445,6 +445,8 @@ let simd_loadop (op : simd_loadop) =
       | Pack16, PackSplat -> "16_splat"
       | Pack32, PackSplat -> "32_splat"
       | Pack64, PackSplat -> "64_splat"
+      | Pack32, PackZero -> "32_zero"
+      | Pack64, PackZero -> "64_zero"
       | _ -> assert false
       ) in
     memop ("load" ^ suffix) op (packed_size sz)