[stubs] Enable machine graph verification for CodeStubAssembler and friends by default in debug mode

test/cctest/test-accessor-assembler.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "test/cctest/cctest.h"
 
 #include "src/base/utils/random-number-generator.h"
 #include "src/ic/accessor-assembler-impl.h"
 #include "src/ic/stub-cache.h"
 #include "test/cctest/compiler/code-assembler-tester.h"
@@ skipping 18 matching lines @@
     Node* name = m.Parameter(0);
     Node* map = m.Parameter(1);
     Node* primary_offset = m.StubCachePrimaryOffsetForTesting(name, map);
     Node* result;
     if (table == StubCache::kPrimary) {
       result = primary_offset;
     } else {
       CHECK_EQ(StubCache::kSecondary, table);
       result = m.StubCacheSecondaryOffsetForTesting(name, primary_offset);
     }
-    m.Return(m.SmiFromWord32(result));
+    m.Return(m.SmiTag(result));
   }
 
   Handle<Code> code = data.GenerateCode();
   FunctionTester ft(code, kNumParams);
 
   Factory* factory = isolate->factory();
   Handle<Name> names[] = {
       factory->NewSymbol(),
       factory->InternalizeUtf8String("a"),
       factory->InternalizeUtf8String("bb"),
@@ skipping 204 matching lines @@
 
     Handle<Object> expected_handler(handler, isolate);
     ft.CheckTrue(receiver, name, expected_handler);
   }
   // Ensure we performed both kind of queries.
   CHECK(queried_existing && queried_non_existing);
 }
 
 }  // namespace internal
 }  // namespace v8