Generalize HeapObject alignment requirements.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index 50d02f9f655e887b10cf5dc4e290d0a343cd7480..b76b2c9764241a50a2bd19400b5d304e1bb60e15 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -2829,23 +2829,16 @@ WriteBarrierMode HeapObject::GetWriteBarrierMode(
 }
 
 
-bool HeapObject::NeedsToEnsureDoubleAlignment() {
+AllocationAlignment HeapObject::RequiredAlignment() {
 #ifdef V8_HOST_ARCH_32_BIT
-  return (IsFixedFloat64Array() || IsFixedDoubleArray() ||
-          IsConstantPoolArray()) &&
-         FixedArrayBase::cast(this)->length() != 0;
-#else
-  return false;
-#endif  // V8_HOST_ARCH_32_BIT
-}
-
-
-bool HeapObject::NeedsToEnsureDoubleUnalignment() {
-#ifdef V8_HOST_ARCH_32_BIT
-  return IsHeapNumber();
-#else
-  return false;
+  if ((IsFixedFloat64Array() || IsFixedDoubleArray() ||
+       IsConstantPoolArray()) &&
+      FixedArrayBase::cast(this)->length() != 0) {
+    return kDoubleAligned;
+  }
+  if (IsHeapNumber()) return kDoubleUnaligned;
 #endif  // V8_HOST_ARCH_32_BIT
+  return kWordAligned;
 }