Fix an off-by-one error in the stack frame iteration.

runtime/vm/raw_object.h

Index: runtime/vm/raw_object.h
diff --git a/runtime/vm/raw_object.h b/runtime/vm/raw_object.h
index 81896b2471af9f5a64bd2da892c08b7d5e43168f..55ac9eea8c00cd5527661cdabef7289b52e454b6 100644
--- a/runtime/vm/raw_object.h
+++ b/runtime/vm/raw_object.h
@@ -789,8 +789,8 @@ class RawStackmap : public RawObject {
     return reinterpret_cast<RawObject**>(&ptr()->bitmap_size_in_bytes_);
   }
   uword pc_;  // PC corresponding to this stack map representation.
-  intptr_t min_set_bit_offset_;  // Minimum bit offset which is set.
-  intptr_t max_set_bit_offset_;  // Maximum bit offset which is set.
+  intptr_t min_set_bit_index_;  // Minimum bit offset which is set.
+  intptr_t max_set_bit_index_;  // Maximum bit offset which is set.
 
   // Variable length data follows here (bitmap of the stack layout).
   uint8_t data_[0];