[turbofan] Add Int32AddWithOverflow machine operator.

src/compiler/register-allocator.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/compiler/register-allocator.h"
 
 #include "src/compiler/linkage.h"
 #include "src/hydrogen.h"
 #include "src/string-stream.h"
 
@@ skipping 801 matching lines @@
         UnallocatedOperand* input_copy =
             cur_input->CopyUnconstrained(code_zone());
         bool is_tagged = HasTaggedValue(cur_input->virtual_register());
         AllocateFixed(cur_input, gap_index + 1, is_tagged);
         AddConstraintsGapMove(gap_index, input_copy, cur_input);
       }
     }
 
     // Handle "output same as input" for second instruction.
     for (size_t i = 0; i < second->OutputCount(); i++) {
-      InstructionOperand* output = second->Output();
+      InstructionOperand* output = second->OutputAt(i);
       if (!output->IsUnallocated()) continue;
       UnallocatedOperand* second_output = UnallocatedOperand::cast(output);
       if (second_output->HasSameAsInputPolicy()) {
-        ASSERT(second->OutputCount() == 1);  // Only valid for one output.
+        ASSERT(i == 0);  // Only valid for first output.
         UnallocatedOperand* cur_input =
             UnallocatedOperand::cast(second->InputAt(0));
         int output_vreg = second_output->virtual_register();
         int input_vreg = cur_input->virtual_register();
 
         UnallocatedOperand* input_copy =
             cur_input->CopyUnconstrained(code_zone());
         cur_input->set_virtual_register(second_output->virtual_register());
         AddConstraintsGapMove(gap_index, input_copy, cur_input);
 
@@ skipping 1320 matching lines @@
                     allocator_zone_start_allocation_size_;
     isolate()->GetTStatistics()->SaveTiming(name(), base::TimeDelta(), size);
   }
 #ifdef DEBUG
   if (allocator_ != NULL) allocator_->Verify();
 #endif
 }
 }
 }
 }  // namespace v8::internal::compiler