MIPS: Workaround for bug in MIPS Android compiler

src/heap/store-buffer.h

Index: src/heap/store-buffer.h
diff --git a/src/heap/store-buffer.h b/src/heap/store-buffer.h
index bf624631865c2564c5edf9ff940dbf61c599b5fc..6c99e1f3dcf48ae7a1f937ab758b06308d3eba16 100644
--- a/src/heap/store-buffer.h
+++ b/src/heap/store-buffer.h
@@ -202,8 +202,8 @@ class StoreBuffer {
 
   // Callbacks are more efficient than reading out the gc state for every
   // store buffer operation.
-  std::function<void(StoreBuffer*, Address)> insertion_callback;
-  std::function<void(StoreBuffer*, Address, Address)> deletion_callback;
+  void (*insertion_callback)(StoreBuffer*, Address);
+  void (*deletion_callback)(StoreBuffer*, Address, Address);
 };
 
 }  // namespace internal