Fix VM product build (linker error)

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/aot_optimizer.h"
 #include "vm/assembler.h"
 #include "vm/ast_printer.h"
 #include "vm/branch_optimizer.h"
@@ skipping 77 matching lines @@
     if ((field_map_ != NULL )&&
         flow_graph->function().IsGenerativeConstructor()) {
       for (BlockIterator block_it = flow_graph->reverse_postorder_iterator();
            !block_it.Done();
            block_it.Advance()) {
         ForwardInstructionIterator it(block_it.Current());
         for (; !it.Done(); it.Advance()) {
           StoreInstanceFieldInstr* store = it.Current()->AsStoreInstanceField();
           if (store != NULL) {
             if (!store->field().IsNull() && store->field().is_final()) {
-              if (FLAG_trace_precompiler) {
+              if (FLAG_trace_precompiler && FLAG_support_il_printer) {
                 THR_Print("Found store to %s <- %s\n",
                           store->field().ToCString(),
                           store->value()->Type()->ToCString());
               }
               FieldTypePair* entry = field_map_->Lookup(&store->field());
               if (entry == NULL) {
                 field_map_->Insert(FieldTypePair(
                     &Field::Handle(zone_, store->field().raw()),  // Re-wrap.
                     store->value()->Type()->ToCid()));
-                if (FLAG_trace_precompiler) {
+                if (FLAG_trace_precompiler && FLAG_support_il_printer) {
                     THR_Print(" initial type = %s\n",
                               store->value()->Type()->ToCString());
                 }
                 continue;
               }
               CompileType type = CompileType::FromCid(entry->cid_);
-              if (FLAG_trace_precompiler) {
+              if (FLAG_trace_precompiler && FLAG_support_il_printer) {
                   THR_Print(" old type = %s\n", type.ToCString());
               }
               type.Union(store->value()->Type());
-              if (FLAG_trace_precompiler) {
+              if (FLAG_trace_precompiler && FLAG_support_il_printer) {
                   THR_Print(" new type = %s\n", type.ToCString());
               }
               entry->cid_ = type.ToCid();
             }
           }
         }
       }
     }
 
     CompileType result_type = CompileType::None();
@@ skipping 3049 matching lines @@
 
   ASSERT(FLAG_precompiled_mode);
   const bool optimized = function.IsOptimizable();  // False for natives.
   DartPrecompilationPipeline pipeline(zone, field_type_map);
   return PrecompileFunctionHelper(&pipeline, function, optimized);
 }
 
 #endif  // DART_PRECOMPILER
 
 }  // namespace dart