[runtime] Unify and simplify how frames are marked

src/compiler/frame.h

Index: src/compiler/frame.h
diff --git a/src/compiler/frame.h b/src/compiler/frame.h
index 011a0f02d5820e07c2064e528bbc0b2d1d8651c1..4c4c2409b46271e9ce9e605c862c77942487a3c9 100644
--- a/src/compiler/frame.h
+++ b/src/compiler/frame.h
@@ -59,9 +59,9 @@ class CallDescriptor;
 //       |- - - - - - - - -|   |                        |
 //   1   | saved frame ptr | Fixed                      |
 //       |- - - - - - - - -| Header <-- frame ptr       |
-//   2   |     Context     |   |                        |
+//   2   |Context/Frm. Type|   |                        |
 //       |- - - - - - - - -|   |                        |
-//   3   |JSFunction/Marker|   v                        |
+//   3   |   [JSFunction]  |   v                        |
 //       +-----------------+----                        |
 //   4   |    spill 1      |   ^                      Callee
 //       |- - - - - - - - -|   |                   frame slots
@@ -115,11 +115,14 @@ class Frame : public ZoneObject {
     return !allocated_double_registers_->IsEmpty();
   }
 
-  int AlignSavedCalleeRegisterSlots() {
+  int AlignSavedCalleeRegisterSlots(int alignment = kDoubleSize) {
     DCHECK_EQ(0, callee_saved_slot_count_);
-    needs_frame_ = true;
-    int delta = frame_slot_count_ & 1;
-    frame_slot_count_ += delta;
+    int alignment_slots = alignment / kPointerSize;
+    int delta = alignment_slots - (frame_slot_count_ & (alignment_slots - 1));
+    if (delta != alignment_slots) {
+      DCHECK(needs_frame_);
+      frame_slot_count_ += delta;
+    }
     return delta;
   }
 
@@ -138,6 +141,8 @@ class Frame : public ZoneObject {
     return slot;
   }
 
+  int AlignFrame(int alignment = kDoubleSize);
+
   int ReserveSpillSlots(size_t slot_count) {
     DCHECK_EQ(0, callee_saved_slot_count_);
     DCHECK_EQ(0, spill_slot_count_);