Add new Float32x4 type for SIMD.js.

src/heap/heap.h

Index: src/heap/heap.h
diff --git a/src/heap/heap.h b/src/heap/heap.h
index 00874798fc53e04ff79239b1c399dc24da8ab9f5..486b6866887f331ef3d242caf87371649d5b2cd8 100644
--- a/src/heap/heap.h
+++ b/src/heap/heap.h
@@ -46,6 +46,7 @@ namespace internal {
   V(Map, meta_map, MetaMap)                                                    \
   V(Map, heap_number_map, HeapNumberMap)                                       \
   V(Map, mutable_heap_number_map, MutableHeapNumberMap)                        \
+  V(Map, float32x4_map, Float32x4Map)                                          \
   V(Map, native_context_map, NativeContextMap)                                 \
   V(Map, fixed_array_map, FixedArrayMap)                                       \
   V(Map, code_map, CodeMap)                                                    \
@@ -342,6 +343,7 @@ namespace internal {
   V(MetaMap)                            \
   V(HeapNumberMap)                      \
   V(MutableHeapNumberMap)               \
+  V(Float32x4Map)                       \
   V(NativeContextMap)                   \
   V(FixedArrayMap)                      \
   V(CodeMap)                            \
@@ -1598,12 +1600,17 @@ class Heap {
                               bool alloc_props = true,
                               AllocationSite* allocation_site = NULL);
 
-  // Allocated a HeapNumber from value.
+  // Allocates a HeapNumber from value.
   MUST_USE_RESULT AllocationResult
       AllocateHeapNumber(double value, MutableMode mode = IMMUTABLE,
                          PretenureFlag pretenure = NOT_TENURED);
 
-  // Allocate a byte array of the specified length
+  // Allocates a Float32x4 from the given lane values.
+  MUST_USE_RESULT AllocationResult
+  AllocateFloat32x4(float w, float x, float y, float z,
+                    PretenureFlag pretenure = NOT_TENURED);
+
+  // Allocates a byte array of the specified length
   MUST_USE_RESULT AllocationResult
       AllocateByteArray(int length, PretenureFlag pretenure = NOT_TENURED);