Bump virtual register width in LUnallocated.

src/lithium.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 164 matching lines @@
   //     +------------------------------------------+    P ... Policy
   //
   // The slot index is a signed value which requires us to decode it manually
   // instead of using the BitField utility class.
 
   // The superclass has a KindField.
   STATIC_ASSERT(kKindFieldWidth == 3);
 
   // BitFields for all unallocated operands.
   class BasicPolicyField     : public BitField<BasicPolicy,     3,  1> {};
-  // TODO(mstarzinger): Bump this from 15 bit to 18 bit in a follow-up CL.
-  class VirtualRegisterField : public BitField<unsigned,        4, 15> {};
+  class VirtualRegisterField : public BitField<unsigned,        4, 18> {};
 
   // BitFields specific to BasicPolicy::FIXED_SLOT.
   class FixedSlotIndexField  : public BitField<int,            22, 10> {};
 
   // BitFields specific to BasicPolicy::EXTENDED_POLICY.
   class ExtendedPolicyField  : public BitField<ExtendedPolicy, 22,  3> {};
   class LifetimeField        : public BitField<Lifetime,       25,  1> {};
   class FixedRegisterField   : public BitField<int,            26,  6> {};
 
   static const int kMaxVirtualRegisters = VirtualRegisterField::kMax + 1;
@@ skipping 575 matching lines @@
   NUMBER_CANDIDATE_IS_SMI,
   NUMBER_CANDIDATE_IS_SMI_OR_HOLE,
   NUMBER_CANDIDATE_IS_SMI_CONVERT_HOLE,
   NUMBER_CANDIDATE_IS_ANY_TAGGED
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_LITHIUM_H_