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

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index ed58f64f6f71a2fa98e6fa4691e43ad3dfae1c27..67c2316ebdeee6463495ca43ebd3af4c7a1b7d44 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -6638,6 +6638,9 @@ class Oddball: public HeapObject {
   static const byte kUndefined = 5;
   static const byte kOther = 6;
 
+  // The ToNumber value of a hidden oddball is a negative smi.
+  static const int kLeastHiddenOddballNumber = -5;
+
   typedef FixedBodyDescriptor<kToStringOffset,
                               kToNumberOffset + kPointerSize,
                               kSize> BodyDescriptor;