Revert of Add SIMD 128 alignment support to Heap.

src/globals.h

Index: src/globals.h
diff --git a/src/globals.h b/src/globals.h
index a7c13733322aaba8226ea480c02e9d8f6f835218..00665e3ffdde2dcd3b0b6d16d2d3af4594aaf018 100644
--- a/src/globals.h
+++ b/src/globals.h
@@ -197,8 +197,6 @@
 const int kOneByteSize    = kCharSize;
 const int kUC16Size     = sizeof(uc16);      // NOLINT
 
-// 128 bit SIMD value size.
-const int kSimd128Size = 16;
 
 // Round up n to be a multiple of sz, where sz is a power of 2.
 #define ROUND_UP(n, sz) (((n) + ((sz) - 1)) & ~((sz) - 1))
@@ -300,10 +298,6 @@
 // Desired alignment for double values.
 const intptr_t kDoubleAlignment = 8;
 const intptr_t kDoubleAlignmentMask = kDoubleAlignment - 1;
-
-// Desired alignment for 128 bit SIMD values.
-const intptr_t kSimd128Alignment = 16;
-const intptr_t kSimd128AlignmentMask = kSimd128Alignment - 1;
 
 // Desired alignment for generated code is 32 bytes (to improve cache line
 // utilization).
@@ -444,12 +438,7 @@
 const int kSpaceTagSize = 3;
 const int kSpaceTagMask = (1 << kSpaceTagSize) - 1;
 
-enum AllocationAlignment {
-  kWordAligned,
-  kDoubleAligned,
-  kDoubleUnaligned,
-  kSimd128Unaligned
-};
+enum AllocationAlignment { kWordAligned, kDoubleAligned, kDoubleUnaligned };
 
 // A flag that indicates whether objects should be pretenured when
 // allocated (allocated directly into the old generation) or not