[csa] Return last value from BuildFastLoop to allow chaining sequential loops

src/code-stub-assembler.h

Index: src/code-stub-assembler.h
diff --git a/src/code-stub-assembler.h b/src/code-stub-assembler.h
index 21ed7daef057edf6009c0893e4d921c3599add97..8844b488d58d07716a75497948e2beecf41e2197 100644
--- a/src/code-stub-assembler.h
+++ b/src/code-stub-assembler.h
@@ -1073,16 +1073,16 @@ class V8_EXPORT_PRIVATE CodeStubAssembler : public compiler::CodeAssembler {
 
   typedef std::function<void(Node* index)> FastLoopBody;
 
-  void BuildFastLoop(const VariableList& var_list,
-                     MachineRepresentation index_rep, Node* start_index,
-                     Node* end_index, const FastLoopBody& body, int increment,
-                     IndexAdvanceMode mode = IndexAdvanceMode::kPre);
-
-  void BuildFastLoop(MachineRepresentation index_rep, Node* start_index,
-                     Node* end_index, const FastLoopBody& body, int increment,
-                     IndexAdvanceMode mode = IndexAdvanceMode::kPre) {
-    BuildFastLoop(VariableList(0, zone()), index_rep, start_index, end_index,
-                  body, increment, mode);
+  Node* BuildFastLoop(const VariableList& var_list,
+                      MachineRepresentation index_rep, Node* start_index,
+                      Node* end_index, const FastLoopBody& body, int increment,
+                      IndexAdvanceMode mode = IndexAdvanceMode::kPre);
+
+  Node* BuildFastLoop(MachineRepresentation index_rep, Node* start_index,
+                      Node* end_index, const FastLoopBody& body, int increment,
+                      IndexAdvanceMode mode = IndexAdvanceMode::kPre) {
+    return BuildFastLoop(VariableList(0, zone()), index_rep, start_index,
+                         end_index, body, increment, mode);
   }
 
   enum class ForEachDirection { kForward, kReverse };