Add flag --always_cleared_ic_data, which forces a cleared ICData to be emitted with each IC call (i…

runtime/vm/flow_graph_compiler.cc

Index: runtime/vm/flow_graph_compiler.cc
===================================================================
--- runtime/vm/flow_graph_compiler.cc	(revision 14363)
+++ runtime/vm/flow_graph_compiler.cc	(working copy)
@@ -26,11 +26,11 @@
 DECLARE_FLAG(bool, code_comments);
 DECLARE_FLAG(bool, enable_type_checks);
 DECLARE_FLAG(bool, intrinsify);
+DECLARE_FLAG(bool, propagate_ic_data);
 DECLARE_FLAG(bool, report_usage_count);
 DECLARE_FLAG(bool, trace_functions);
 DECLARE_FLAG(int, optimization_counter_threshold);
 
-
 void CompilerDeoptInfo::BuildReturnAddress(DeoptInfoBuilder* builder,
                                            const Function& function,
                                            intptr_t slot_ix) {
@@ -476,6 +476,7 @@
     LocationSummary* locs,
     const ICData& ic_data) {
   ASSERT(!ic_data.IsNull());
+  ASSERT(FLAG_propagate_ic_data || (ic_data.NumberOfChecks() == 0));
   // Because optimized code should not waste time.
   ASSERT(!is_optimizing() || ic_data.num_args_tested() == 1);
   const Array& arguments_descriptor =