Add dynamic stack frame alignment to optimized functions with untagged doubles on the stack.

src/ia32/lithium-ia32.cc

Index: src/ia32/lithium-ia32.cc
diff --git a/src/ia32/lithium-ia32.cc b/src/ia32/lithium-ia32.cc
index 6f87a256c57da9b565f4c00119d7434f3ef54d46..050afd944e12a4d9b9f1c4c6a411c7c6478e4a1b 100644
--- a/src/ia32/lithium-ia32.cc
+++ b/src/ia32/lithium-ia32.cc
@@ -352,7 +352,11 @@ void LAccessArgumentsAt::PrintDataTo(StringStream* stream) {
 
 int LChunk::GetNextSpillIndex(bool is_double) {
   // Skip a slot if for a double-width slot.
-  if (is_double) spill_slot_count_++;
+  if (is_double) {
+    spill_slot_count_ |= 1;  // Make it odd, so incrementing makes it even.
+    spill_slot_count_++;
+    num_double_slots_++;
+  }
   return spill_slot_count_++;
 }