Improve internal compiler API so that OSR code is never installed on function.

runtime/vm/dart_entry.cc

 // Copyright (c) 2011, 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/dart_entry.h"
 
 #include "vm/class_finalizer.h"
 #include "vm/code_generator.h"
 #include "vm/compiler.h"
 #include "vm/debugger.h"
@@ skipping 78 matching lines @@
                                      const Array& arguments_descriptor,
                                      uword current_sp) {
   // Get the entrypoint corresponding to the function specified, this
   // will result in a compilation of the function if it is not already
   // compiled.
   Thread* thread = Thread::Current();
   Zone* zone = thread->zone();
   ASSERT(thread->IsMutatorThread());
   ScopedIsolateStackLimits stack_limit(thread, current_sp);
   if (!function.HasCode()) {
-    const Error& error =
-        Error::Handle(zone, Compiler::CompileFunction(thread, function));
-    if (!error.IsNull()) {
-      return error.raw();
+    const Object& result =
+        Object::Handle(zone, Compiler::CompileFunction(thread, function));
+    if (result.IsError()) {
+      return Error::Cast(result).raw();
     }
   }
 // Now Call the invoke stub which will invoke the dart function.
 #if !defined(TARGET_ARCH_DBC)
   invokestub entrypoint = reinterpret_cast<invokestub>(
       StubCode::InvokeDartCode_entry()->EntryPoint());
 #endif
   const Code& code = Code::Handle(zone, function.CurrentCode());
   ASSERT(!code.IsNull());
   ASSERT(thread->no_callback_scope_depth() == 0);
@@ skipping 473 matching lines @@
   const Array& args = Array::Handle(Array::New(kNumArguments));
   args.SetAt(0, map);
   args.SetAt(1, key);
   args.SetAt(2, value);
   const Object& result =
       Object::Handle(DartEntry::InvokeFunction(function, args));
   return result.raw();
 }
 
 }  // namespace dart