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

src/wasm/wasm-external-refs.cc

 // Copyright 2016 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 <math.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <limits>
 
 #include "include/v8config.h"
@@ skipping 190 matching lines @@
 
 uint32_t word64_popcnt_wrapper(uint64_t* input) {
   return static_cast<uint32_t>(base::bits::CountPopulation(*input));
 }
 
 void float64_pow_wrapper(double* param0, double* param1) {
   double x = ReadDoubleValue(param0);
   double y = ReadDoubleValue(param1);
   WriteDoubleValue(param0, Pow(x, y));
 }
+
+static WasmTrapCallbackForTesting wasm_trap_callback_for_testing = nullptr;
+
+void set_trap_callback_for_testing(WasmTrapCallbackForTesting callback) {
+  wasm_trap_callback_for_testing = callback;
+}
+
+void call_trap_callback_for_testing() {
+  if (wasm_trap_callback_for_testing) {
+    wasm_trap_callback_for_testing();
+  }
+}
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8