[turbofan] Make MachineType a pair of enums.

src/compiler/c-linkage.cc

 // Copyright 2015 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/assembler.h"
 #include "src/macro-assembler.h"
 
 #include "src/compiler/linkage.h"
 
 #include "src/zone.h"
@@ skipping 190 matching lines @@
   const RegList kCalleeSaveRegisters = 0;
 #endif
 
 #ifdef CALLEE_SAVE_FP_REGISTERS
   const RegList kCalleeSaveFPRegisters = CALLEE_SAVE_FP_REGISTERS;
 #else
   const RegList kCalleeSaveFPRegisters = 0;
 #endif
 
   // The target for C calls is always an address (i.e. machine pointer).
-  MachineType target_type = kMachPtr;
+  MachineType target_type = MachineType::Pointer();
   LinkageLocation target_loc = LinkageLocation::ForAnyRegister();
   return new (zone) CallDescriptor(  // --
       CallDescriptor::kCallAddress,  // kind
       target_type,                   // target MachineType
       target_loc,                    // target location
       msig,                          // machine_sig
       locations.Build(),             // location_sig
       0,                             // stack_parameter_count
       Operator::kNoProperties,       // properties
       kCalleeSaveRegisters,          // callee-saved registers
       kCalleeSaveFPRegisters,        // callee-saved fp regs
       CallDescriptor::kNoFlags,      // flags
       "c-call");
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8