Deal with missing deopt_table under precompilation.

runtime/vm/object.cc

Index: runtime/vm/object.cc
diff --git a/runtime/vm/object.cc b/runtime/vm/object.cc
index 20ae404501636be9c5e5bb9539eedc922067fb28..d5917a11937441fedca999480eb85fe0757e041e 100644
--- a/runtime/vm/object.cc
+++ b/runtime/vm/object.cc
@@ -13056,7 +13056,10 @@ RawTypedData* Code::GetDeoptInfoAtPc(uword pc,
   const Instructions& instrs = Instructions::Handle(instructions());
   uword code_entry = instrs.EntryPoint();
   const Array& table = Array::Handle(deopt_info_array());
-  ASSERT(!table.IsNull());
+  if (table.IsNull()) {
+    ASSERT(Dart::IsRunningPrecompiledCode());
+    return TypedData::null();
+  }
   // Linear search for the PC offset matching the target PC.
   intptr_t length = DeoptTable::GetLength(table);
   Smi& offset = Smi::Handle();