[builtins] FastNewFunctionContextStub becomes a builtin

src/full-codegen/x64/full-codegen-x64.cc

Index: src/full-codegen/x64/full-codegen-x64.cc
diff --git a/src/full-codegen/x64/full-codegen-x64.cc b/src/full-codegen/x64/full-codegen-x64.cc
index eab035fee4a4fc52aabcd632f0e0a4c5f3f33109..bb06eab7383baf84700eb1363003ee215a8d6acf 100644
--- a/src/full-codegen/x64/full-codegen-x64.cc
+++ b/src/full-codegen/x64/full-codegen-x64.cc
@@ -4,15 +4,16 @@
 
 #if V8_TARGET_ARCH_X64
 
-#include "src/full-codegen/full-codegen.h"
 #include "src/ast/compile-time-value.h"
 #include "src/ast/scopes.h"
+#include "src/builtins/builtins-constructor.h"
 #include "src/code-factory.h"
 #include "src/code-stubs.h"
 #include "src/codegen.h"
 #include "src/compilation-info.h"
 #include "src/compiler.h"
 #include "src/debug/debug.h"
+#include "src/full-codegen/full-codegen.h"
 #include "src/ic/ic.h"
 
 namespace v8 {
@@ -187,11 +188,13 @@ void FullCodeGenerator::Generate() {
       if (info->scope()->new_target_var() != nullptr) {
         __ Push(rdx);  // Preserve new target.
       }
-      if (slots <= FastNewFunctionContextStub::MaximumSlots()) {
-        FastNewFunctionContextStub stub(isolate(), info->scope()->scope_type());
+      if (slots <=
+          ConstructorBuiltinsAssembler::MaximumFunctionContextSlots()) {
+        Callable callable = CodeFactory::FastNewFunctionContext(
+            isolate(), info->scope()->scope_type());
         __ Set(FastNewFunctionContextDescriptor::SlotsRegister(), slots);
-        __ CallStub(&stub);
-        // Result of FastNewFunctionContextStub is always in new space.
+        __ Call(callable.code(), RelocInfo::CODE_TARGET);
+        // Result of the FastNewFunctionContext builtin is always in new space.
         need_write_barrier = false;
       } else {
         __ Push(rdi);