VM: Add dart_precompiled build target, a standalone VM without the JIT compiler.

runtime/vm/precompiler.cc

 // Copyright (c) 2015, 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/precompiler.h"
 
 #include "vm/code_patcher.h"
 #include "vm/compiler.h"
 #include "vm/isolate.h"
 #include "vm/log.h"
@@ skipping 570 matching lines @@
     }
   }
 }
 
 
 void Precompiler::AddInstantiatedClass(const Class& cls) {
   if (cls.is_allocated()) return;
 
   class_count_++;
   cls.set_is_allocated(true);
+  cls.EnsureIsFinalized(T);

[rmacnak, 2015/11/17 20:51:18]

All the classes should have been finalized before we get here.

[Florian Schneider, 2015/11/18 11:44:09]

Not true for certain signature classes: If you set a breakpoint in
EnsureFinalized when running a precompiled snapshot you'll see which ones.

There may be something missing in the tree-shaking code though.

[rmacnak, 2015/11/18 19:00:07]

Oh, right. Signature classes may be created as we parse functions.

   changed_ = true;
 
   if (FLAG_trace_precompiler) {
     THR_Print("Allocation %" Pd " %s\n", class_count_, cls.ToCString());
   }
 
   const Class& superclass = Class::Handle(cls.SuperClass());
   if (!superclass.IsNull()) {
     AddInstantiatedClass(superclass);
   }
@@ skipping 353 matching lines @@
       cls = it.GetNextClass();
       if (cls.IsDynamicClass()) {
         continue;  // class 'dynamic' is in the read-only VM isolate.
       }
       cls.set_is_allocated(false);
     }
   }
 }
 
 }  // namespace dart