[wasm] [fuzzer] Bound the number of steps to execute

To avoid running infinitely or hitting the stack size limit, bound the
number of steps to execute in the interpreter to 16k.

R=ahaas@chromium.org
BUG=chromium:708457

Change-Id: Ib101bbbc06627641dae2fd1cd1a8d950aa504eaf
Reviewed-on: https://chromium-review.googlesource.com/469609
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44446}

test/common/wasm/wasm-module-runner.cc

@@ -115,6 +115,9 @@ int32_t InterpretWasmModule(Isolate* isolate, ErrorThrower* thrower,
                             const ModuleWireBytes& wire_bytes,
                             int function_index, WasmVal* args,
                             bool* possible_nondeterminism) {
+  // Don't execute more than 16k steps.
+  constexpr int kMaxNumSteps = 16 * 1024;
+
   DCHECK_NOT_NULL(module);
   Zone zone(isolate->allocator(), ZONE_NAME);
   v8::internal::HandleScope scope(isolate);
@@ -144,7 +147,7 @@ int32_t InterpretWasmModule(Isolate* isolate, ErrorThrower* thrower,
   WasmInterpreter::Thread* thread = interpreter.GetThread(0);
   thread->Reset();
   thread->InitFrame(&(module->functions[function_index]), args);
-  WasmInterpreter::State interpreter_result = thread->Run();
+  WasmInterpreter::State interpreter_result = thread->Run(kMaxNumSteps);
   if (instance.mem_start) {
     free(instance.mem_start);
   }