Fix bugs in simplified lowering relating to int32/uint32 signs.

test/unittests/compiler/machine-operator-reducer-unittest.cc

 // Copyright 2014 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 "src/base/bits.h"
 #include "src/base/division-by-constant.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/machine-operator-reducer.h"
 #include "src/compiler/typer.h"
 #include "test/unittests/compiler/graph-unittest.h"
 #include "test/unittests/compiler/node-test-utils.h"
 #include "testing/gmock-support.h"
 
 using testing::AllOf;
 using testing::Capture;
 using testing::CaptureEq;
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 class MachineOperatorReducerTest : public TypedGraphTest {
  public:
   explicit MachineOperatorReducerTest(int num_parameters = 2)
-      : TypedGraphTest(num_parameters) {}
+      : TypedGraphTest(num_parameters), machine_(zone()) {}
 
  protected:
   Reduction Reduce(Node* node) {
     JSOperatorBuilder javascript(zone());
     JSGraph jsgraph(graph(), common(), &javascript, &machine_);
     MachineOperatorReducer reducer(&jsgraph);
     return reducer.Reduce(node);
   }
 
   Matcher<Node*> IsTruncatingDiv(const Matcher<Node*>& dividend_matcher,
@@ skipping 1182 matching lines @@
     Reduction r = Reduce(node);
     ASSERT_TRUE(r.Changed());
     EXPECT_THAT(r.replacement(),
                 IsStore(rep, base, index, value, effect, control));
   }
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8