Revert of Add SIMD 128 alignment support to Heap.

src/heap/heap.cc

Index: src/heap/heap.cc
diff --git a/src/heap/heap.cc b/src/heap/heap.cc
index b596b6e14dd6f29d47536bc5d657d743dd7cd076..b7cc3299cfea764fb94748c7c8a5876ba71e9310 100644
--- a/src/heap/heap.cc
+++ b/src/heap/heap.cc
@@ -1993,8 +1993,6 @@
     case kDoubleAligned:
     case kDoubleUnaligned:
       return kDoubleSize - kPointerSize;
-    case kSimd128Unaligned:
-      return kSimd128Size - kPointerSize;
     default:
       UNREACHABLE();
   }
@@ -2008,10 +2006,6 @@
     return kPointerSize;
   if (alignment == kDoubleUnaligned && (offset & kDoubleAlignmentMask) == 0)
     return kDoubleSize - kPointerSize;  // No fill if double is always aligned.
-  if (alignment == kSimd128Unaligned) {
-    return (kSimd128Size - (static_cast<int>(offset) + kPointerSize)) &
-           kSimd128AlignmentMask;
-  }
   return 0;
 }