Pass around the current isolate in exception handling code.

runtime/vm/bigint_operations.cc

Index: runtime/vm/bigint_operations.cc
diff --git a/runtime/vm/bigint_operations.cc b/runtime/vm/bigint_operations.cc
index 0c1847640b2fb3d9a8ba115d9bece068b8acb2dc..e8cafdc5d10f948e0cd156214a2930067fad0f17 100644
--- a/runtime/vm/bigint_operations.cc
+++ b/runtime/vm/bigint_operations.cc
@@ -358,7 +358,7 @@ const char* BigintOperations::ToDecimalCString(
     // into dart code or allocating any code.
     const Instance& exception =
         Instance::Handle(isolate->object_store()->out_of_memory());
-    Exceptions::Throw(exception);
+    Exceptions::Throw(isolate, exception);
     UNREACHABLE();
   }