Revert of [cleanup] Refactor builtins-number.cc (patchset #2 id:40001 of...

Revert of [cleanup] Refactor builtins-number.cc (patchset #2 id:40001 of https://codereview.chromium.org/2517833005/ )

Reason for revert:
Secondary dependency to revert https://codereview.chromium.org/2522393002/

Original issue's description:
> [cleanup] Refactor builtins-number.cc
>
> Introducing a TF_BUILTIN macro that wraps CodeStubAssembler usage
> into a convenient interface (using a subclass under the hood).
>
> Committed: https://crrev.com/cbf59c4c704e83a43b52c5ba6825df576fdaece8
> Cr-Commit-Position: refs/heads/master@{#41236}

TBR=ishell@chromium.org,jkummerow@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true

Review-Url: https://codereview.chromium.org/2529873002
Cr-Commit-Position: refs/heads/master@{#41252}

src/builtins/builtins-utils.h

@@ -101,31 +101,6 @@ class BuiltinArguments : public Arguments {
   MUST_USE_RESULT static Object* Builtin_Impl_##name(BuiltinArguments args,   \
                                                      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)                                  \