[cleanup] Refactor builtins-number.cc

src/builtins/builtins-utils.h

Index: src/builtins/builtins-utils.h
diff --git a/src/builtins/builtins-utils.h b/src/builtins/builtins-utils.h
index 6378fdfad5d3413b8d826ae5bb6ccde2e9b05955..80e0d29f17ec42303a0ef0c7185546be09d17b4f 100644
--- a/src/builtins/builtins-utils.h
+++ b/src/builtins/builtins-utils.h
@@ -102,6 +102,31 @@ class BuiltinArguments : public Arguments {
                                                      Isolate* isolate)
 
 // ----------------------------------------------------------------------------
+// Support macro for defining builtins with Turbofan.
+// ----------------------------------------------------------------------------
+//
+// A builtin function is defined by writing:
+//
+//   TF_BUILTIN(name, code_assember_base_class) {
+//     ...
+//   }
+//
+// In the body of the builtin function the arguments can be accessed
+// as "Parameter(n)".
+#define TF_BUILTIN(Name, AssemblerBase)                                 \
+  class Name##Assembler : public AssemblerBase {                        \
+   public:                                                              \
+    explicit Name##Assembler(compiler::CodeAssemblerState* state)       \
+        : AssemblerBase(state) {}                                       \
+    void Generate##Name();                                              \
+  };                                                                    \
+  void Builtins::Generate_##Name(compiler::CodeAssemblerState* state) { \
+    Name##Assembler assembler(state);                                   \
+    assembler.Generate##Name();                                         \
+  }                                                                     \
+  void Name##Assembler::Generate##Name()
+
+// ----------------------------------------------------------------------------
 
 #define CHECK_RECEIVER(Type, name, method)                                  \
   if (!args.receiver()->Is##Type()) {                                       \