More simplification and unification of frame handling

src/crankshaft/lithium.cc

Index: src/crankshaft/lithium.cc
diff --git a/src/crankshaft/lithium.cc b/src/crankshaft/lithium.cc
index 82ad6962be43e121badea6907aa1e62f9b5010f2..677639095a522f64a9729a6100ad5f8472df79d6 100644
--- a/src/crankshaft/lithium.cc
+++ b/src/crankshaft/lithium.cc
@@ -246,22 +246,9 @@ void LPointerMap::PrintTo(StringStream* stream) {
   stream->Add("}");
 }
 
-
-int StackSlotOffset(int index) {
-  if (index >= 0) {
-    // Local or spill slot. Skip the frame pointer, function, and
-    // context in the fixed part of the frame.
-    return -(index + 1) * kPointerSize -
-        StandardFrameConstants::kFixedFrameSizeFromFp;
-  } else {
-    // Incoming parameter. Skip the return address.
-    return -(index + 1) * kPointerSize + kFPOnStackSize + kPCOnStackSize;
-  }
-}
-
-
 LChunk::LChunk(CompilationInfo* info, HGraph* graph)
-    : spill_slot_count_(0),
+    : base_frame_slots_(StandardFrameConstants::kFixedFrameSize / kPointerSize),
+      current_frame_slots_(base_frame_slots_),
       info_(info),
       graph_(graph),
       instructions_(32, info->zone()),
@@ -270,7 +257,6 @@ LChunk::LChunk(CompilationInfo* info, HGraph* graph)
       deprecation_dependencies_(32, info->zone()),
       stability_dependencies_(8, info->zone()) {}
 
-
 LLabel* LChunk::GetLabel(int block_id) const {
   HBasicBlock* block = graph_->blocks()->at(block_id);
   int first_instruction = block->first_instruction_index();
@@ -495,9 +481,9 @@ void LChunk::set_allocated_double_registers(BitVector* allocated_registers) {
   while (!iterator.Done()) {
     if (info()->saves_caller_doubles()) {
       if (kDoubleSize == kPointerSize * 2) {
-        spill_slot_count_ += 2;
+        current_frame_slots_ += 2;
       } else {
-        spill_slot_count_++;
+        current_frame_slots_++;
       }
     }
     iterator.Advance();