[ubsan] Fix HeapObjectMatcher to avoid invalid casts.

src/compiler/js-builtin-reducer.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/compiler/diamond.h"
 #include "src/compiler/js-builtin-reducer.h"
 #include "src/compiler/js-graph.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 #include "src/types.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 
 // Helper class to access JSCallFunction nodes that are potential candidates
 // for reduction when they have a BuiltinFunctionId associated with them.
 class JSCallReduction {
  public:
   explicit JSCallReduction(Node* node) : node_(node) {}
 
   // Determines whether the node is a JSCallFunction operation that targets a
   // constant callee being a well-known builtin with a BuiltinFunctionId.
   bool HasBuiltinFunctionId() {
     if (node_->opcode() != IrOpcode::kJSCallFunction) return false;
-    HeapObjectMatcher<Object> m(NodeProperties::GetValueInput(node_, 0));
+    HeapObjectMatcher m(NodeProperties::GetValueInput(node_, 0));
     if (!m.HasValue() || !m.Value().handle()->IsJSFunction()) return false;
     Handle<JSFunction> function = Handle<JSFunction>::cast(m.Value().handle());
     return function->shared()->HasBuiltinFunctionId();
   }
 
   // Retrieves the BuiltinFunctionId as described above.
   BuiltinFunctionId GetBuiltinFunctionId() {
     DCHECK_EQ(IrOpcode::kJSCallFunction, node_->opcode());
-    HeapObjectMatcher<Object> m(NodeProperties::GetValueInput(node_, 0));
+    HeapObjectMatcher m(NodeProperties::GetValueInput(node_, 0));
     Handle<JSFunction> function = Handle<JSFunction>::cast(m.Value().handle());
     return function->shared()->builtin_function_id();
   }
 
   // Determines whether the call takes zero inputs.
   bool InputsMatchZero() { return GetJSCallArity() == 0; }
 
   // Determines whether the call takes one input of the given type.
   bool InputsMatchOne(Type* t1) {
     return GetJSCallArity() == 1 &&
@@ skipping 132 matching lines @@
 }
 
 
 MachineOperatorBuilder* JSBuiltinReducer::machine() const {
   return jsgraph()->machine();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8