Clean up aligned allocation code in preparation for SIMD alignments.

src/globals.h

Index: src/globals.h
diff --git a/src/globals.h b/src/globals.h
index 761983178d4b0f4d2f316744eed9d4ff818474e4..10caab29739e3fcb59684c0522c5e0ead1eb1f73 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -438,7 +438,7 @@ enum AllocationSpace {
 const int kSpaceTagSize = 3;
 const int kSpaceTagMask = (1 << kSpaceTagSize) - 1;
 
-enum AllocationAlignment { kWordAligned, kDoubleAligned, kDoubleUnaligned };
+enum AllocationAlignment { kWordAligned, kDoubleAligned, kDoubleValueAligned };
 
 // A flag that indicates whether objects should be pretenured when
 // allocated (allocated directly into the old generation) or not