[turbofan] Change TruncateFloat32ToUint64 to TryTruncateFloat32ToUint64.

src/compiler/ppc/instruction-selector-ppc.cc

 // Copyright 2014 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/base/adapters.h"
 #include "src/compiler/instruction-selector-impl.h"
 #include "src/compiler/node-matchers.h"
 #include "src/compiler/node-properties.h"
 #include "src/ppc/frames-ppc.h"
 
@@ skipping 931 matching lines @@
 
   Node* success_output = NodeProperties::FindProjection(node, 1);
   if (success_output) {
     outputs[output_count++] = g.DefineAsRegister(success_output);
   }
 
   Emit(kPPC_DoubleToInt64, output_count, outputs, 1, inputs);
 }
 
 
-void InstructionSelector::VisitTruncateFloat32ToUint64(Node* node) {
+void InstructionSelector::VisitTryTruncateFloat32ToUint64(Node* node) {
+  if (NodeProperties::FindProjection(node, 1)) {
+    // TODO(ppc): implement the second return value.
+    UNIMPLEMENTED();
+  }
   VisitRR(this, kPPC_DoubleToUint64, node);
 }
 
 
 void InstructionSelector::VisitTryTruncateFloat64ToUint64(Node* node) {
   PPCOperandGenerator g(this);
 
   InstructionOperand inputs[] = {g.UseRegister(node->InputAt(0))};
   InstructionOperand outputs[2];
   size_t output_count = 0;
@@ skipping 756 matching lines @@
          MachineOperatorBuilder::kFloat64RoundTruncate |
          MachineOperatorBuilder::kFloat64RoundTiesAway |
          MachineOperatorBuilder::kWord32Popcnt |
          MachineOperatorBuilder::kWord64Popcnt;
   // We omit kWord32ShiftIsSafe as s[rl]w use 0x3f as a mask rather than 0x1f.
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8