Implement TypedArray.set function.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 3fa1a4098f4b870748e13419feecd42be112f015..7a7b32c76facb3ad0bec2d302fa058f749059c07 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -13452,6 +13452,33 @@ ExternalArrayType JSTypedArray::type() {
 }
 
 
+size_t JSTypedArray::element_size() {
+  switch (elements()->map()->instance_type()) {
+    case EXTERNAL_BYTE_ARRAY_TYPE:
+      return 1;
+    case EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE:
+      return 1;
+    case EXTERNAL_SHORT_ARRAY_TYPE:
+      return 2;
+    case EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE:
+      return 2;
+    case EXTERNAL_INT_ARRAY_TYPE:
+      return 4;
+    case EXTERNAL_UNSIGNED_INT_ARRAY_TYPE:
+      return 4;
+    case EXTERNAL_FLOAT_ARRAY_TYPE:
+      return 4;
+    case EXTERNAL_DOUBLE_ARRAY_TYPE:
+      return 8;
+    case EXTERNAL_PIXEL_ARRAY_TYPE:
+      return 1;
+    default:
+      UNREACHABLE();
+      return 0;
+  }
+}
+
+
 Object* ExternalPixelArray::SetValue(uint32_t index, Object* value) {
   uint8_t clamped_value = 0;
   if (index < static_cast<uint32_t>(length())) {