ICData::NumberOfChecks is O(n) so don't call it in loops

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index 84656ed580b6ffe27148810bafbc507befec56b3..6daa41497c14db3084f903386507829ef3929345 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -1918,11 +1918,16 @@ class ICData : public Object {
   // the final one.
   intptr_t Length() const;
 
+  // Takes O(result) time!
   intptr_t NumberOfChecks() const;
 
   // Discounts any checks with usage of zero.
+  // Takes O(result)) time!
   intptr_t NumberOfUsedChecks() const;
 
+  // Takes O(n) time!
+  bool NumberOfChecksIs(intptr_t n) const;
+
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawICData));
   }