[kernel] Fix call to NameIndex(NULL)

runtime/vm/kernel_binary_flowgraph.cc

 // Copyright (c) 2016, 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/kernel_binary_flowgraph.h"
 
 #include "vm/longjump.h"
 #include "vm/object_store.h"
 
 #if !defined(DART_PRECOMPILED_RUNTIME)
@@ skipping 1327 matching lines @@
   return name_index;
 }
 
 const dart::String& StreamingFlowGraphBuilder::ReadNameAsMethodName() {
   StringIndex name_index = ReadStringReference();  // read name index.
   if ((H.StringSize(name_index) >= 1) && H.CharacterAt(name_index, 0) == '_') {
     NameIndex library_reference =
         ReadCanonicalNameReference();  // read library index.
     return H.DartMethodName(library_reference, name_index);
   } else {
-    return H.DartMethodName(NameIndex(NULL), name_index);
+    return H.DartMethodName(NameIndex(), name_index);
   }
 }
 
 const dart::String& StreamingFlowGraphBuilder::ReadNameAsSetterName() {
   StringIndex name_index = ReadStringReference();  // read name index.
   if ((H.StringSize(name_index) >= 1) && H.CharacterAt(name_index, 0) == '_') {
     NameIndex library_reference =
         ReadCanonicalNameReference();  // read library index.
     return H.DartSetterName(library_reference, name_index);
   } else {
-    return H.DartSetterName(NameIndex(NULL), name_index);
+    return H.DartSetterName(NameIndex(), name_index);
   }
 }
 
 const dart::String& StreamingFlowGraphBuilder::ReadNameAsGetterName() {
   StringIndex name_index = ReadStringReference();  // read name index.
   if ((H.StringSize(name_index) >= 1) && H.CharacterAt(name_index, 0) == '_') {
     NameIndex library_reference =
         ReadCanonicalNameReference();  // read library index.
     return H.DartGetterName(library_reference, name_index);
   } else {
-    return H.DartGetterName(NameIndex(NULL), name_index);
+    return H.DartGetterName(NameIndex(), name_index);
   }
 }
 
 void StreamingFlowGraphBuilder::SkipStringReference() {
   ReadUInt();
 }
 
 void StreamingFlowGraphBuilder::SkipCanonicalNameReference() {
   ReadUInt();
 }
@@ skipping 2930 matching lines @@
   }
   instructions += StoreLocal(position, variable);
   instructions += Drop();
   return instructions;
 }
 
 }  // namespace kernel
 }  // namespace dart
 
 #endif  // !defined(DART_PRECOMPILED_RUNTIME)