Expose SIMD.Float32x4 type to Javascript.

src/contexts.h

Index: src/contexts.h
diff --git a/src/contexts.h b/src/contexts.h
index 529e1c47ff4c5fb07b5b4da9e8075530dd24e56d..fc29831942645a8cce99de3472e4908b178df8d2 100644
--- a/src/contexts.h
+++ b/src/contexts.h
@@ -81,6 +81,7 @@ enum BindingFlags {
   V(STRING_FUNCTION_INDEX, JSFunction, string_function)                        \
   V(STRING_FUNCTION_PROTOTYPE_MAP_INDEX, Map, string_function_prototype_map)   \
   V(SYMBOL_FUNCTION_INDEX, JSFunction, symbol_function)                        \
+  V(FLOAT32X4_FUNCTION_INDEX, JSFunction, float32x4_function)                  \
   V(OBJECT_FUNCTION_INDEX, JSFunction, object_function)                        \
   V(JS_OBJECT_STRONG_MAP_INDEX, Map, js_object_strong_map)                     \
   V(INTERNAL_ARRAY_FUNCTION_INDEX, JSFunction, internal_array_function)        \
@@ -358,6 +359,7 @@ class Context: public FixedArray {
     STRING_FUNCTION_INDEX,
     STRING_FUNCTION_PROTOTYPE_MAP_INDEX,
     SYMBOL_FUNCTION_INDEX,
+    FLOAT32X4_FUNCTION_INDEX,
     OBJECT_FUNCTION_INDEX,
     JS_OBJECT_STRONG_MAP_INDEX,
     INTERNAL_ARRAY_FUNCTION_INDEX,