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

runtime/vm/unit_test.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/unit_test.h"
 
 #include <stdio.h>
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
@@ skipping 454 matching lines @@
     OS::Print("Error compiling test script:\n%s\n", error.ToErrorCString());
   }
   return error.IsNull();
 }
 
 
 bool CompilerTest::TestCompileFunction(const Function& function) {
   Thread* thread = Thread::Current();
   ASSERT(thread != NULL);
   ASSERT(ClassFinalizer::AllClassesFinalized());
-  const Error& error =
-      Error::Handle(Compiler::CompileFunction(thread, function));
-  return error.IsNull();
+  const Object& result =
+      Object::Handle(Compiler::CompileFunction(thread, function));
+  return result.IsCode();
 }
 
 
 void ElideJSONSubstring(const char* prefix, const char* in, char* out) {
   const char* pos = strstr(in, prefix);
   while (pos != NULL) {
     // Copy up to pos into the output buffer.
     while (in < pos) {
       *out++ = *in++;
     }
 
     // Skip to the close quote.
     in += strcspn(in, "\"");
     pos = strstr(in, prefix);
   }
   // Copy the remainder of in to out.
   while (*in != '\0') {
     *out++ = *in++;
   }
   *out = '\0';
 }
 
 
 }  // namespace dart