[turbofan]: Add better encapsulation to LinkageLocation

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"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 namespace {
 // Platform-specific configuration for C calling convention.
 LinkageLocation regloc(Register reg) {
-  return LinkageLocation(Register::ToAllocationIndex(reg));
+  return LinkageLocation::ForRegister(Register::ToAllocationIndex(reg));
 }
 
 
 LinkageLocation stackloc(int i) {
   DCHECK_LT(i, 0);
-  return LinkageLocation(i);
+  return LinkageLocation::ForCallerFrameSlot(i);
 }
 
 
 #if V8_TARGET_ARCH_IA32
 // ===========================================================================
 // == ia32 ===================================================================
 // ===========================================================================
 #define RETURN_REGISTER_0 eax
 #define RETURN_REGISTER_1 edx
 #define CALLEE_SAVE_REGISTERS esi.bit() | edi.bit() | ebx.bit()
@@ skipping 183 matching lines @@
 #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;
-  LinkageLocation target_loc = LinkageLocation::AnyRegister();
+  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,                             // js_parameter_count
       Operator::kNoProperties,       // properties
       kCalleeSaveRegisters,          // callee-saved registers
       kCalleeSaveFPRegisters,        // callee-saved fp regs
       CallDescriptor::kNoFlags,      // flags
       "c-call");
 }
 }
 }
 }