Refactor register allocator a little bit

src/lithium-allocator-inl.h

Index: src/lithium-allocator-inl.h
diff --git a/src/lithium-allocator-inl.h b/src/lithium-allocator-inl.h
index 8cca19b2efa738c927ed51156faa24373ecd1e49..deee98877d6cd9f718024ca6b9dd1fe69f76f8fc 100644
--- a/src/lithium-allocator-inl.h
+++ b/src/lithium-allocator-inl.h
@@ -145,16 +145,14 @@ void UseIterator::Advance() {
 }
 
 
-void LAllocator::SetLiveRangeAssignedRegister(
-    LiveRange* range,
-    int reg,
-    RegisterKind register_kind) {
-  if (register_kind == DOUBLE_REGISTERS) {
+void LAllocator::SetLiveRangeAssignedRegister(LiveRange* range, int reg) {
+  if (range->Kind() == DOUBLE_REGISTERS) {
     assigned_double_registers_->Add(reg);
   } else {
+    ASSERT(range->Kind() == GENERAL_REGISTERS);
     assigned_registers_->Add(reg);
   }
-  range->set_assigned_register(reg, register_kind, chunk()->zone());
+  range->set_assigned_register(reg, chunk()->zone());
 }