null value can be the receiver of methods on Object (e.g. hashCode).

runtime/vm/compiler.cc

Index: runtime/vm/compiler.cc
diff --git a/runtime/vm/compiler.cc b/runtime/vm/compiler.cc
index 4513bae19dc6d135585096a2d08a158efffad40d..229402aefe2741638b930e86be38274c16d4b7be 100644
--- a/runtime/vm/compiler.cc
+++ b/runtime/vm/compiler.cc
@@ -112,14 +112,6 @@ static void InstallUnoptimizedCode(const Function& function) {
 }
 
 
-static void PrintGraph(const char* phase, FlowGraph* flow_graph) {
-  OS::Print("*** BEGIN CFG\n%s\n", phase);
-  FlowGraphPrinter printer(*flow_graph);
-  printer.PrintBlocks();
-  OS::Print("*** END CFG\n");
-}
-
-
 // Return false if bailed out.
 static bool CompileParsedFunctionHelper(const ParsedFunction& parsed_function,
                                         bool optimized) {
@@ -172,7 +164,7 @@ static bool CompileParsedFunctionHelper(const ParsedFunction& parsed_function,
 
     if (FLAG_print_flow_graph ||
         (optimized && FLAG_print_flow_graph_optimized)) {
-      PrintGraph("Before Optimizations", flow_graph);
+      FlowGraphPrinter::PrintGraph("Before Optimizations", flow_graph);
     }
 
     if (optimized) {
@@ -263,7 +255,7 @@ static bool CompileParsedFunctionHelper(const ParsedFunction& parsed_function,
       allocator.AllocateRegisters();
 
       if (FLAG_print_flow_graph || FLAG_print_flow_graph_optimized) {
-        PrintGraph("After Optimizations", flow_graph);
+        FlowGraphPrinter::PrintGraph("After Optimizations", flow_graph);
       }
     }