[wasm] Fix wasm decoder tracing for prefix opcodes.

src/wasm/wasm-opcodes.cc

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/wasm/wasm-opcodes.h"
 #include "src/messages.h"
 #include "src/signature.h"
 
 namespace v8 {
 namespace internal {
@@ skipping 20 matching lines @@
   case kExpr##name:                          \
     return #name;
     FOREACH_OPCODE(DECLARE_NAME_CASE)
 #undef DECLARE_NAME_CASE
     default:
       break;
   }
   return "Unknown";
 }
 
+bool WasmOpcodes::IsPrefixOpcode(WasmOpcode opcode) {
+  switch (opcode) {
+#define CHECK_PREFIX(name, opcode) \
+  case k##name##Prefix:            \
+    return true;
+    FOREACH_PREFIX(CHECK_PREFIX)
+#undef CHECK_PREFIX
+    default:
+      return false;
+  }
+}
+
 std::ostream& operator<<(std::ostream& os, const FunctionSig& sig) {
   if (sig.return_count() == 0) os << "v";
   for (size_t i = 0; i < sig.return_count(); ++i) {
     os << WasmOpcodes::ShortNameOf(sig.GetReturn(i));
   }
   os << "_";
   if (sig.parameter_count() == 0) os << "v";
   for (size_t i = 0; i < sig.parameter_count(); ++i) {
     os << WasmOpcodes::ShortNameOf(sig.GetParam(i));
   }
@@ skipping 85 matching lines @@
       return MessageTemplate::kNone;
   }
 }
 
 const char* WasmOpcodes::TrapReasonMessage(TrapReason reason) {
   return MessageTemplate::TemplateString(TrapReasonToMessageId(reason));
 }
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8