Set output representation of HIsStringAndBranch to tagged.

BUG=chromium:421877
LOG=N
R=jkummerow@chromium.org

Review URL: https://codereview.chromium.org/641313003

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24521 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.h

@@ -4477,11 +4477,12 @@ class HIsStringAndBranch FINAL : public HUnaryControlInstruction {
   virtual int RedefinedOperandIndex() { return 0; }
 
  private:
-  HIsStringAndBranch(HValue* value,
-                     HBasicBlock* true_target = NULL,
+  HIsStringAndBranch(HValue* value, HBasicBlock* true_target = NULL,
                      HBasicBlock* false_target = NULL)
-    : HUnaryControlInstruction(value, true_target, false_target),
-      known_successor_index_(kNoKnownSuccessorIndex) { }
+      : HUnaryControlInstruction(value, true_target, false_target),
+        known_successor_index_(kNoKnownSuccessorIndex) {
+    set_representation(Representation::Tagged());
+  }
 
   int known_successor_index_;
 };