Fix a crash due to enabling VTune JIT support

When VTune JIT support is enabled, the WasmEngine of an Isolate tries to
enable code logging by EnableCodeLogging() method. This multithreaded
method requires a Mutex for safety. However, as the WasmEngine is not
created, the Mutex of it is not initialized. An attempt of acquiring
this Mutex results in an error. The bug is fixed by creating WasmEngine
before it enables code logging.

Change-Id: I59e749190288ec412f6661233e8f62b0dff3cd7f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1337376Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#60060}

src/log.cc

@@ -1930,7 +1930,9 @@ void Logger::SetCodeEventHandler(uint32_t options,
   }
 
   if (event_handler) {
-    isolate_->wasm_engine()->EnableCodeLogging(isolate_);
+    if (isolate_->wasm_engine() != nullptr) {
+      isolate_->wasm_engine()->EnableCodeLogging(isolate_);
+    }
     jit_logger_.reset(new JitLogger(isolate_, event_handler));
     AddCodeEventListener(jit_logger_.get());
     if (options & kJitCodeEventEnumExisting) {