Use IC register definitions in platform files.

src/x64/debug-x64.cc

Index: src/x64/debug-x64.cc
diff --git a/src/x64/debug-x64.cc b/src/x64/debug-x64.cc
index 4703e42354746586dfc2558173d0563089800493..f0f8198c16cf1fe727755d13ea140e8c8e966542 100644
--- a/src/x64/debug-x64.cc
+++ b/src/x64/debug-x64.cc
@@ -162,11 +162,9 @@ void DebugCodegen::GenerateCallICStubDebugBreak(MacroAssembler* masm) {
 
 void DebugCodegen::GenerateLoadICDebugBreak(MacroAssembler* masm) {
   // Register state for IC load call (from ic-x64.cc).
-  // ----------- S t a t e -------------
-  //  -- rax    : receiver
-  //  -- rcx    : name
-  // -----------------------------------
-  Generate_DebugBreakCallHelper(masm, rax.bit() | rcx.bit(), 0, false);
+  Register receiver = LoadIC::ReceiverRegister();
+  Register name = LoadIC::NameRegister();
+  Generate_DebugBreakCallHelper(masm, receiver.bit() | name.bit(), 0, false);
 }
 
 
@@ -184,11 +182,9 @@ void DebugCodegen::GenerateStoreICDebugBreak(MacroAssembler* masm) {
 
 void DebugCodegen::GenerateKeyedLoadICDebugBreak(MacroAssembler* masm) {
   // Register state for keyed IC load call (from ic-x64.cc).
-  // ----------- S t a t e -------------
-  //  -- rax     : key
-  //  -- rdx     : receiver
-  // -----------------------------------
-  Generate_DebugBreakCallHelper(masm, rax.bit() | rdx.bit(), 0, false);
+  Register receiver = KeyedLoadIC::ReceiverRegister();
+  Register name = KeyedLoadIC::NameRegister();
+  Generate_DebugBreakCallHelper(masm, receiver.bit() | name.bit(), 0, false);
 }