[builtins] FastNewFunctionContextStub becomes a builtin

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index 77e4f2aa55264c21772d8353e1182b2594035860..e089fb3f4200e542513b45e890fb6b2f5cb0cb4e 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -99,7 +99,6 @@ class Node;
   V(FastCloneRegExp)                          \
   V(FastCloneShallowArray)                    \
   V(FastCloneShallowObject)                   \
-  V(FastNewFunctionContext)                   \
   V(KeyedLoadSloppyArguments)                 \
   V(KeyedStoreSloppyArguments)                \
   V(LoadScriptContextField)                   \
@@ -768,40 +767,6 @@ class NumberToStringStub final : public TurboFanCodeStub {
   DEFINE_TURBOFAN_CODE_STUB(NumberToString, TurboFanCodeStub);
 };
 
-class FastNewFunctionContextStub final : public TurboFanCodeStub {
- public:
-  static int MaximumSlots();
-
-  explicit FastNewFunctionContextStub(Isolate* isolate, ScopeType scope_type)
-      : TurboFanCodeStub(isolate) {
-    minor_key_ = ScopeTypeBits::encode(scope_type);
-  }
-
-  static compiler::Node* Generate(CodeStubAssembler* assembler,
-                                  compiler::Node* function,
-                                  compiler::Node* slots,
-                                  compiler::Node* context,
-                                  ScopeType scope_type);
-
-  ScopeType scope_type() const {
-    return static_cast<ScopeType>(ScopeTypeBits::decode(minor_key_));
-  }
-
- private:
-  static const int kMaximumSlots = 0x8000;
-  static const int kSmallMaximumSlots = 10;
-
-  // FastNewFunctionContextStub can only allocate closures which fit in the
-  // new space.
-  STATIC_ASSERT(((kMaximumSlots + Context::MIN_CONTEXT_SLOTS) * kPointerSize +
-                 FixedArray::kHeaderSize) < kMaxRegularHeapObjectSize);
-
-  class ScopeTypeBits : public BitField<bool, 0, 8> {};
-
-  DEFINE_CALL_INTERFACE_DESCRIPTOR(FastNewFunctionContext);
-  DEFINE_TURBOFAN_CODE_STUB(FastNewFunctionContext, TurboFanCodeStub);
-};
-
 // TODO(turbofan): This stub should be possible to write in TurboFan
 // using the CodeStubAssembler very soon in a way that is as efficient
 // and easy as the current handwritten version, which is partly a copy