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

src/compiler/arm64/code-generator-arm64.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/code-generator.h"
 
 #include "src/arm64/frames-arm64.h"
 #include "src/arm64/macro-assembler-arm64.h"
 #include "src/compilation-info.h"
 #include "src/compiler/code-generator-impl.h"
@@ skipping 1684 matching lines @@
     __ B(cc, tlabel);
   }
   if (!branch->fallthru) __ B(flabel);  // no fallthru to flabel.
 }
 
 
 void CodeGenerator::AssembleArchJump(RpoNumber target) {
   if (!IsNextInAssemblyOrder(target)) __ B(GetLabel(target));
 }
 
+void CodeGenerator::AssembleArchTrap(Instruction* instr,
+                                     FlagsCondition condition) {
+  UNREACHABLE();
+}
 
 // Assemble boolean materializations after this instruction.
 void CodeGenerator::AssembleArchBoolean(Instruction* instr,
                                         FlagsCondition condition) {
   Arm64OperandConverter i(this, instr);
 
   // Materialize a full 64-bit 1 or 0 value. The result register is always the
   // last output of the instruction.
   DCHECK_NE(0u, instr->OutputCount());
   Register reg = i.OutputRegister(instr->OutputCount() - 1);
@@ skipping 401 matching lines @@
       padding_size -= kInstructionSize;
     }
   }
 }
 
 #undef __
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8