[wasm] Import table only after checks

With recent spec changes (I think in the bulk memory proposal),
WebAssembly instances exist and can be used even when instantiation
itself fails. Therefore the order of checks and assignents during
instantiation may matter. That's why I move the table import after the
checks of the import in this CL.

Note that I'm not aware that this is a problem yet. I think in the worst
case this CL has no effect. In the best case it helps.

R=clemensh@chromium.org

Bug: v8:9396
Change-Id: I83998ff98bded443b3f015cee778fa29a3374534
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1678656Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62409}

src/wasm/module-instantiate.cc

@@ -941,7 +941,6 @@ bool InstanceBuilder::ProcessImportedTable(Handle<WasmInstanceObject> instance,
   }
   const WasmTable& table = module_->tables[table_index];
 
-  instance->tables().set(table_index, *value);
   auto table_object = Handle<WasmTableObject>::cast(value);
 
   int imported_table_size = table_object->entries().length();
@@ -985,6 +984,7 @@ bool InstanceBuilder::ProcessImportedTable(Handle<WasmInstanceObject> instance,
     return false;
   }
 
+  instance->tables().set(table_index, *value);
   return true;
 }