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

src/wasm/wasm-external-refs.h

Index: src/wasm/wasm-external-refs.h
diff --git a/src/wasm/wasm-external-refs.h b/src/wasm/wasm-external-refs.h
index d9539ce71a8869f71cbc3e6a7ecaf89214529a89..04337b99ec24f13cd7a0a0650ec2d87133019af2 100644
--- a/src/wasm/wasm-external-refs.h
+++ b/src/wasm/wasm-external-refs.h
@@ -61,6 +61,12 @@ uint32_t word64_popcnt_wrapper(uint64_t* input);
 
 void float64_pow_wrapper(double* param0, double* param1);
 
+typedef void (*WasmTrapCallbackForTesting)();
+
+void set_trap_callback_for_testing(WasmTrapCallbackForTesting callback);
+
+void call_trap_callback_for_testing();
+
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8