[turbofan] Eliminate typed array bounds checks if both key and length are constant.

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 718803f314243bec661bccf0dbf99e495f16d724..3e64ddd4f7b337202cd93ceac55a1911f3a26181 100644
--- a/src/compiler/node-matchers.h
+++ b/src/compiler/node-matchers.h
@@ -96,6 +96,41 @@ typedef FloatMatcher<double, IrOpcode::kFloat64Constant> Float64Matcher;
 typedef FloatMatcher<double, IrOpcode::kNumberConstant> NumberMatcher;
 
 
+// A pattern matcher for any numberic constant.
+struct NumericValueMatcher : public NodeMatcher {
+  explicit NumericValueMatcher(Node* const node) : NodeMatcher(node) {
+    switch (opcode()) {
+      case IrOpcode::kInt32Constant:
+        has_value_ = true;
+        value_ = OpParameter<int32_t>(node);
+        break;
+      case IrOpcode::kFloat32Constant:
+        has_value_ = true;
+        value_ = OpParameter<float>(node);
+        break;
+      case IrOpcode::kFloat64Constant:
+      case IrOpcode::kNumberConstant:
+        has_value_ = true;
+        value_ = OpParameter<double>(node);
+        break;
+      default:
+        has_value_ = false;
+        break;
+    }
+  }
+
+  bool HasValue() const { return has_value_; }
+  double Value() const {
+    DCHECK(HasValue());
+    return value_;
+  }
+
+ private:
+  double value_;
+  bool has_value_;
+};
+
+
 // A pattern matcher for heap object constants.
 template <typename T>
 struct HeapObjectMatcher FINAL