[Interpreter] Collect String feedback on CompareOps.

src/type-hints.cc

Index: src/type-hints.cc
diff --git a/src/type-hints.cc b/src/type-hints.cc
index 1c40c59b6398a6849c33900ed36c5f3fa496949a..56542e5264e179031443a47f074af611ad80a20e 100644
--- a/src/type-hints.cc
+++ b/src/type-hints.cc
@@ -36,6 +36,8 @@ std::ostream& operator<<(std::ostream& os, CompareOperationHint hint) {
       return os << "Number";
     case CompareOperationHint::kNumberOrOddball:
       return os << "NumberOrOddball";
+    case CompareOperationHint::kString:
+      return os << "String";
     case CompareOperationHint::kAny:
       return os << "Any";
   }