[wasm] Load undefined value from the wasm instance

In export wrappers generated code, load the undefined value from the
wasm instance rather than from the isolate. With asynchronous
compilation, the isolate may not be available.

R=mstarzinger@chromium.org

Bug: v8:9554
Change-Id: Ic448bda82c2125fc9c9f8715bce26870308715d2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1722556Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62946}

src/compiler/wasm-compiler.cc

@@ -5598,8 +5598,9 @@ class WasmWrapperGraphBuilder : public WasmGraphBuilder {
     // Clear the ThreadInWasm flag.
     BuildModifyThreadInWasmFlag(false);
 
-    Node* jsval = sig_->return_count() == 0 ? jsgraph()->UndefinedConstant()
-                                            : ToJS(rets[0], sig_->GetReturn());
+    Node* jsval = sig_->return_count() == 0
+                      ? BuildLoadUndefinedValueFromInstance()
+                      : ToJS(rets[0], sig_->GetReturn());
     Return(jsval);
   }