Add CODE_POINTER_ALIGN, use it in Page to align generated code.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 6c4af25297c874f30c5f4c5b6b91083037583a8a..24401ebcfd178133a7a9e86022c3f2873e8d4632 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -3009,11 +3009,6 @@ class Code: public HeapObject {
   void CodePrint();
   void CodeVerify();
 #endif
-  // Code entry points are aligned to 32 bytes.
-  static const int kCodeAlignmentBits = 5;
-  static const int kCodeAlignment = 1 << kCodeAlignmentBits;
-  static const int kCodeAlignmentMask = kCodeAlignment - 1;
-
   // Layout description.
   static const int kInstructionSizeOffset = HeapObject::kHeaderSize;
   static const int kRelocationInfoOffset = kInstructionSizeOffset + kIntSize;
@@ -3022,8 +3017,7 @@ class Code: public HeapObject {
   // Add padding to align the instruction start following right after
   // the Code object header.
   static const int kHeaderSize =
-      (kKindSpecificFlagsOffset + kIntSize + kCodeAlignmentMask) &
-          ~kCodeAlignmentMask;
+      CODE_POINTER_ALIGN(kKindSpecificFlagsOffset + kIntSize);
 
   // Byte offsets within kKindSpecificFlagsOffset.
   static const int kStubMajorKeyOffset = kKindSpecificFlagsOffset + 1;