[wasm] Reduce NativeModuleCache overhead

When inserting the temporary cache key for synchronous compilation, use
the NativeModule's owned wire bytes. When we eventually install the
native module, key comparison can then take the fast path by checking
base pointer equality instead comparing the full bytes.

R=clemensb@chromium.org

Bug: chromium:1035786, v8:10576
Change-Id: I4bfb948b4383d58dd11060a7d1d1e0495ddeed2a
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2246559Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68342}

src/wasm/module-compiler.cc

@@ -1429,9 +1429,15 @@ std::shared_ptr<NativeModule> CompileToNativeModule(
     std::shared_ptr<const WasmModule> module, const ModuleWireBytes& wire_bytes,
     Handle<FixedArray>* export_wrappers_out) {
   const WasmModule* wasm_module = module.get();
+  OwnedVector<uint8_t> wire_bytes_copy =
+      OwnedVector<uint8_t>::Of(wire_bytes.module_bytes());
+  // Prefer {wire_bytes_copy} to {wire_bytes.module_bytes()} for the temporary
+  // cache key. When we eventually install the module in the cache, the wire
+  // bytes of the temporary key and the new key have the same base pointer and
+  // we can skip the full bytes comparison.
   std::shared_ptr<NativeModule> native_module =
       isolate->wasm_engine()->MaybeGetNativeModule(
-          wasm_module->origin, wire_bytes.module_bytes(), isolate);
+          wasm_module->origin, wire_bytes_copy.as_vector(), isolate);
   if (native_module) {
     // TODO(thibaudm): Look into sharing export wrappers.
     CompileJsToWasmWrappers(isolate, wasm_module, export_wrappers_out);
@@ -1445,8 +1451,6 @@ std::shared_ptr<NativeModule> CompileToNativeModule(
   if (wasm_module->has_shared_memory) {
     isolate->CountUsage(v8::Isolate::UseCounterFeature::kWasmSharedMemory);
   }
-  OwnedVector<uint8_t> wire_bytes_copy =
-      OwnedVector<uint8_t>::Of(wire_bytes.module_bytes());
 
   // Create a new {NativeModule} first.
   const bool uses_liftoff = module->origin == kWasmOrigin && FLAG_liftoff;