Do not eagerly compile the function implementation class in case of an error.

runtime/vm/bootstrap.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/bootstrap.h"
 
 #include "include/dart_api.h"
 
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
@@ skipping 297 matching lines @@
                              patch_uri,
                              bootstrap_libraries[i].patch_paths_);
       if (!error.IsNull()) {
         break;
       }
     }
   }
   if (error.IsNull()) {
     SetupNativeResolver();
     ClassFinalizer::ProcessPendingClasses();
+
+    Class& cls = Class::Handle(isolate);
+    // Eagerly compile the function implementation class as it is the super
+    // class of signature classes. This allows us to just finalize signature
+    // classes without going through the hoops of trying to compile them.
+    const Type& type =
+        Type::Handle(isolate, isolate->object_store()->function_impl_type());
+    cls = type.type_class();
+    Compiler::CompileClass(cls);
   }
 
-  Class& cls = Class::Handle(isolate);
-  // Eagerly compile the function implementation class as it is the super
-  // class of signature classes. This allows us to just finalize signature
-  // classes without going through the hoops of trying to compile them.
-  const Type& type =
-      Type::Handle(isolate, isolate->object_store()->function_impl_type());
-  cls = type.type_class();
-  Compiler::CompileClass(cls);
-
   // Restore the library tag handler for the isolate.
   isolate->set_library_tag_handler(saved_tag_handler);
 
   return error.raw();
 }
 
 }  // namespace dart