Fix bailout from the optimizing-mode compiler and put SSA construction under a flag.

vm/compiler.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/compiler.h"
 
 #include "vm/assembler.h"
 #include "vm/ast_printer.h"
 #include "vm/code_generator.h"
 #include "vm/code_patcher.h"
@@ skipping 315 matching lines @@
   TimerScope timer(FLAG_compiler_stats, &CompilerStats::codegen_timer);
   bool is_compiled = false;
   // TODO(srdjan): Remove once the old compiler has been ripped out.
 #if defined(TARGET_ARCH_X64)
   const bool use_new_compiler = true;
 #else
   const bool use_new_compiler = FLAG_use_new_compiler;
 #endif
   if (use_new_compiler) {
     is_compiled = CompileWithNewCompiler(parsed_function, optimized);
+    if (!is_compiled && optimized) {
+      // When bailing out from the optimizing compiler, mark function as
+      // non-optimizable and return.
+      parsed_function.function().set_is_optimizable(false);
+      return;
+    }
   }
 
   if (!is_compiled) {
     CompileWithOldCompiler(parsed_function, optimized);
   }
 }
 
 
 static RawError* CompileFunctionHelper(const Function& function,
                                        bool optimized) {
@@ skipping 201 matching lines @@
     isolate->object_store()->clear_sticky_error();
     isolate->set_long_jump_base(base);
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 
 }  // namespace dart