[turbofan] Initial import of SimplifiedOperatorReducer.

src/compiler/node-matchers.h

Index: src/compiler/node-matchers.h
diff --git a/src/compiler/node-matchers.h b/src/compiler/node-matchers.h
index 3b34d07c08f921d112d8bf378b495ecd8ce9a027..136fa529cd3e99d3d0f301cfb2dbcc96f6e7730c 100644
--- a/src/compiler/node-matchers.h
+++ b/src/compiler/node-matchers.h
@@ -6,6 +6,7 @@
 #define V8_COMPILER_NODE_MATCHERS_H_
 
 #include "src/compiler/common-operator.h"
+#include "src/compiler/node.h"
 
 namespace v8 {
 namespace internal {
@@ -92,6 +93,18 @@ struct FloatMatcher V8_FINAL : public ValueMatcher<T> {
 typedef FloatMatcher<double> Float64Matcher;
 
 
+// A pattern matcher for heap object constants.
+struct HeapObjectMatcher V8_FINAL
+    : public ValueMatcher<PrintableUnique<HeapObject> > {
+  explicit HeapObjectMatcher(Node* node)
+      : ValueMatcher<PrintableUnique<HeapObject> >(node) {}
+
+  bool IsKnownGlobal(HeapObject* global) const {
+    return HasValue() && Value().IsKnownGlobal(global);
+  }
+};
+
+
 // For shorter pattern matching code, this struct matches both the left and
 // right hand sides of a binary operation and can put constants on the right
 // if they appear on the left hand side of a commutative operation.