Remove frame pointer from StackHandler.

src/frames.cc

Index: src/frames.cc
diff --git a/src/frames.cc b/src/frames.cc
index 61fab874d6148bcbc7e3d711948e172c91cf13d4..e3584476b675f7c56fe9ae90c199186e68adcb85 100644
--- a/src/frames.cc
+++ b/src/frames.cc
@@ -1534,17 +1534,16 @@ void StackHandler::Unwind(Isolate* isolate,
                           FixedArray* array,
                           int offset,
                           int previous_handler_offset) const {
-  STATIC_ASSERT(StackHandlerConstants::kSlotCount >= 4);
+  STATIC_ASSERT(StackHandlerConstants::kSlotCount >= 3);
   DCHECK_LE(0, offset);
   DCHECK_GE(array->length(), offset + StackHandlerConstants::kSlotCount);
   // Unwinding a stack handler into an array chains it in the opposite
   // direction, re-using the "next" slot as a "previous" link, so that stack
-  // handlers can be later re-wound in the correct order.  Decode the "state"
-  // slot into "index" and "kind" and store them separately, using the fp slot.
-  array->set(offset, Smi::FromInt(previous_handler_offset));        // next
-  array->set(offset + 1, Smi::FromInt(static_cast<int>(index())));  // state
-  array->set(offset + 2, *context_address());                       // context
-  array->set(offset + 3, Smi::FromInt(static_cast<int>(kind())));   // fp
+  // handlers can be later re-wound in the correct order.
+  int s = Memory::int_at(address() + StackHandlerConstants::kStateIntOffset);
+  array->set(offset, Smi::FromInt(previous_handler_offset));  // next
+  array->set(offset + 1, Smi::FromInt(static_cast<int>(s)));  // state
+  array->set(offset + 2, *context_address());                 // context
 
   *isolate->handler_address() = next()->address();
 }
@@ -1554,23 +1553,19 @@ int StackHandler::Rewind(Isolate* isolate,
                          FixedArray* array,
                          int offset,
                          Address fp) {
-  STATIC_ASSERT(StackHandlerConstants::kSlotCount >= 4);
+  STATIC_ASSERT(StackHandlerConstants::kSlotCount >= 3);
   DCHECK_LE(0, offset);
   DCHECK_GE(array->length(), offset + StackHandlerConstants::kSlotCount);
   Smi* prev_handler_offset = Smi::cast(array->get(offset));
-  Smi* smi_index = Smi::cast(array->get(offset + 1));
+  Smi* smi_state = Smi::cast(array->get(offset + 1));
   Object* context = array->get(offset + 2);
-  Smi* smi_kind = Smi::cast(array->get(offset + 3));
-
-  unsigned state = KindField::encode(static_cast<Kind>(smi_kind->value())) |
-      IndexField::encode(static_cast<unsigned>(smi_index->value()));
 
   Memory::Address_at(address() + StackHandlerConstants::kNextOffset) =
       *isolate->handler_address();
-  Memory::uintptr_at(address() + StackHandlerConstants::kStateOffset) = state;
+  Memory::int_at(address() + StackHandlerConstants::kStateIntOffset) =
+      smi_state->value();
   Memory::Object_at(address() + StackHandlerConstants::kContextOffset) =
       context;
-  SetFp(address() + StackHandlerConstants::kFPOffset, fp);
 
   *isolate->handler_address() = address();