Add --parse-all option in order to benchmark and measure the scanner/parser performance.

runtime/vm/flow_graph_builder.cc

Index: runtime/vm/flow_graph_builder.cc
diff --git a/runtime/vm/flow_graph_builder.cc b/runtime/vm/flow_graph_builder.cc
index 79285e9619a9ae87be43529d3681e45fc65f9949..8d865636c9c79d92533679d9750136f4c497054d 100644
--- a/runtime/vm/flow_graph_builder.cc
+++ b/runtime/vm/flow_graph_builder.cc
@@ -4598,10 +4598,12 @@ FlowGraph* FlowGraphBuilder::BuildGraph() {
                       FLAG_profile_vm);
   if (FLAG_support_ast_printer && FLAG_print_ast) {
     // Print the function ast before IL generation.
-    AstPrinter::PrintFunctionNodes(parsed_function());
+    AstPrinter ast_printer;
+    ast_printer.PrintFunctionNodes(parsed_function());
   }
   if (FLAG_support_ast_printer && FLAG_print_scopes) {
-    AstPrinter::PrintFunctionScope(parsed_function());
+    AstPrinter ast_printer;
+    ast_printer.PrintFunctionScope(parsed_function());
   }
   TargetEntryInstr* normal_entry =
       new(Z) TargetEntryInstr(AllocateBlockId(),