[wasm] Introduce the TrapIf and TrapUnless operators to generate trap code.

src/compiler/instruction.cc

 // Copyright 2014 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/compiler/common-operator.h"
 #include "src/compiler/graph.h"
 #include "src/compiler/instruction.h"
 #include "src/compiler/schedule.h"
 #include "src/compiler/state-values-utils.h"
 
@@ skipping 415 matching lines @@
 std::ostream& operator<<(std::ostream& os, const FlagsMode& fm) {
   switch (fm) {
     case kFlags_none:
       return os;
     case kFlags_branch:
       return os << "branch";
     case kFlags_deoptimize:
       return os << "deoptimize";
     case kFlags_set:
       return os << "set";
+    case kFlags_trap:
+      return os << "trap";
   }
   UNREACHABLE();
   return os;
 }
 
 
 std::ostream& operator<<(std::ostream& os, const FlagsCondition& fc) {
   switch (fc) {
     case kEqual:
       return os << "equal";
@@ skipping 628 matching lines @@
   for (int i = 0; i < code.InstructionBlockCount(); i++) {
     printable_block.block_ = code.InstructionBlockAt(RpoNumber::FromInt(i));
     os << printable_block;
   }
   return os;
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8