[wasm] Fix nullptr dereference

Skip code spaces that do not have a far jump table in GetRuntimeStubId.

R=clemensb@chromium.org

Bug: chromium:1116141
Change-Id: Id0fcec691a2729f67750d2da15eea9f521075743
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2366763Reviewed-by: Clemens Backes <clemensb@chromium.org>
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69512}

src/wasm/wasm-code-manager.cc

@@ -1487,7 +1487,8 @@ WasmCode::RuntimeStubId NativeModule::GetRuntimeStubId(Address target) const {
   base::MutexGuard guard(&allocation_mutex_);
 
   for (auto& code_space_data : code_space_data_) {
-    if (code_space_data.far_jump_table->contains(target)) {
+    if (code_space_data.far_jump_table != nullptr &&
+        code_space_data.far_jump_table->contains(target)) {
       uint32_t offset = static_cast<uint32_t>(
           target - code_space_data.far_jump_table->instruction_start());
       uint32_t index = JumpTableAssembler::FarJumpSlotOffsetToIndex(offset);