Use IC register definitions in platform files.

src/x64/lithium-x64.cc

Index: src/x64/lithium-x64.cc
diff --git a/src/x64/lithium-x64.cc b/src/x64/lithium-x64.cc
index 6d772c01c6243d016cdeeb61172b59ccf02723bc..c1022fbc17de46d9cc8c897ad4eacb9cad9f7408 100644
--- a/src/x64/lithium-x64.cc
+++ b/src/x64/lithium-x64.cc
@@ -2040,7 +2040,8 @@ LInstruction* LChunkBuilder::DoLoadGlobalCell(HLoadGlobalCell* instr) {
 
 LInstruction* LChunkBuilder::DoLoadGlobalGeneric(HLoadGlobalGeneric* instr) {
   LOperand* context = UseFixed(instr->context(), rsi);
-  LOperand* global_object = UseFixed(instr->global_object(), rax);
+  LOperand* global_object = UseFixed(instr->global_object(),
+                                     LoadIC::ReceiverRegister());
   LLoadGlobalGeneric* result =
       new(zone()) LLoadGlobalGeneric(context, global_object);
   return MarkAsCall(DefineFixed(result, rax), instr);
@@ -2107,7 +2108,7 @@ LInstruction* LChunkBuilder::DoLoadNamedField(HLoadNamedField* instr) {
 
 LInstruction* LChunkBuilder::DoLoadNamedGeneric(HLoadNamedGeneric* instr) {
   LOperand* context = UseFixed(instr->context(), rsi);
-  LOperand* object = UseFixed(instr->object(), rax);
+  LOperand* object = UseFixed(instr->object(), LoadIC::ReceiverRegister());
   LLoadNamedGeneric* result = new(zone()) LLoadNamedGeneric(context, object);
   return MarkAsCall(DefineFixed(result, rax), instr);
 }
@@ -2193,8 +2194,8 @@ LInstruction* LChunkBuilder::DoLoadKeyed(HLoadKeyed* instr) {
 
 LInstruction* LChunkBuilder::DoLoadKeyedGeneric(HLoadKeyedGeneric* instr) {
   LOperand* context = UseFixed(instr->context(), rsi);
-  LOperand* object = UseFixed(instr->object(), rdx);
-  LOperand* key = UseFixed(instr->key(), rax);
+  LOperand* object = UseFixed(instr->object(), KeyedLoadIC::ReceiverRegister());
+  LOperand* key = UseFixed(instr->key(), KeyedLoadIC::NameRegister());
 
   LLoadKeyedGeneric* result =
       new(zone()) LLoadKeyedGeneric(context, object, key);