Copy ICData descriptors when starting background compilation, so that they do not change while comp…

runtime/vm/coverage.cc

Index: runtime/vm/coverage.cc
diff --git a/runtime/vm/coverage.cc b/runtime/vm/coverage.cc
index 73fb5b67ce1d73001f724b8910522a1f8cda2b3e..9c38d8b4db214a43942cd862f9cc447896dbc3bd 100644
--- a/runtime/vm/coverage.cc
+++ b/runtime/vm/coverage.cc
@@ -83,7 +83,7 @@ void CodeCoverage::CompileAndAdd(const Function& function,
   // Print the hit counts for all IC datas.
   ZoneGrowableArray<const ICData*>* ic_data_array =
       new(zone) ZoneGrowableArray<const ICData*>();
-  function.RestoreICDataMap(ic_data_array);
+  function.RestoreICDataMap(ic_data_array, false /* clone descriptors */);
   const PcDescriptors& descriptors = PcDescriptors::Handle(
       zone, code.pc_descriptors());