[turbofan] Add comments to CodeAssembler

src/code-stub-assembler.cc

Index: src/code-stub-assembler.cc
diff --git a/src/code-stub-assembler.cc b/src/code-stub-assembler.cc
index 27f39a7f1068e2006f26c5a42d0426687ea85c7c..5ec36c2f3911727ed1ae00334a161b8f0cfcba0a 100644
--- a/src/code-stub-assembler.cc
+++ b/src/code-stub-assembler.cc
@@ -772,6 +772,8 @@ Node* CodeStubAssembler::AllocateJSArray(ElementsKind kind, Node* array_map,
   int base_size = JSArray::kSize + FixedArray::kHeaderSize;
   int elements_offset = JSArray::kSize;
 
+  Comment("begin allocation of JSArray");
+
   if (allocation_site != nullptr) {
     base_size += AllocationMemento::kSize;
     elements_offset += AllocationMemento::kSize;