[wasm] Remove double check for --experimental-wasm-simd flag

src/wasm/function-body-decoder.cc

Index: src/wasm/function-body-decoder.cc
diff --git a/src/wasm/function-body-decoder.cc b/src/wasm/function-body-decoder.cc
index 29b90ec61ffe3cdf64e10eb9ed66172c8ead6360..0dfbf33d317151cad45e37e082a4718998e31c0e 100644
--- a/src/wasm/function-body-decoder.cc
+++ b/src/wasm/function-body-decoder.cc
@@ -1615,11 +1615,9 @@ class WasmFullDecoder : public WasmDecoder {
         break;
       }
       case kExprS128LoadMem:
-        CHECK_PROTOTYPE_OPCODE(simd);
         len = DecodePrefixedLoadMem(kWasmS128, MachineType::Simd128());
         break;
       case kExprS128StoreMem:
-        CHECK_PROTOTYPE_OPCODE(simd);
         len = DecodePrefixedStoreMem(kWasmS128, MachineType::Simd128());
         break;
       default: {