[wasm] Add missing type enum in switch statement and remove default

R=jkummerow@chromium.org

Bug: chromium:1043036
Change-Id: Idf44e21254a5d7131c4ec6e4c22fa4d4b25f617b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2016590Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Emanuel Ziegler <ecmziegler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65967}

test/common/wasm/wasm-module-runner.cc

@@ -103,11 +103,14 @@ bool InterpretWasmModuleForTesting(Isolate* isolate,
         break;
       case kWasmAnyRef:
       case kWasmFuncRef:
+      case kWasmNullRef:
       case kWasmExnRef:
         arguments[i] =
             WasmValue(Handle<Object>::cast(isolate->factory()->null_value()));
         break;
-      default:
+      case kWasmStmt:
+      case kWasmBottom:
+      case kWasmS128:
         UNREACHABLE();
     }
   }