Make FastNewFunctionContextStub take slots parameter

src/full-codegen/arm64/full-codegen-arm64.cc

Index: src/full-codegen/arm64/full-codegen-arm64.cc
diff --git a/src/full-codegen/arm64/full-codegen-arm64.cc b/src/full-codegen/arm64/full-codegen-arm64.cc
index ad63bf6d81cb652faf6dc47ff6331e44eb08854e..2603d981ab574b9596ccfd7ca1417f337ff90e38 100644
--- a/src/full-codegen/arm64/full-codegen-arm64.cc
+++ b/src/full-codegen/arm64/full-codegen-arm64.cc
@@ -187,15 +187,11 @@ void FullCodeGenerator::Generate() {
       if (info->scope()->new_target_var() != nullptr) {
         __ Push(x3);  // Preserve new target.
       }
-      if (slots <= FastNewFunctionContextStub::kMaximumSlots) {
-        FastNewFunctionContextStub stub(isolate(), slots);
-        __ CallStub(&stub);
-        // Result of FastNewFunctionContextStub is always in new space.
-        need_write_barrier = false;
-      } else {
-        __ Push(x1);
-        __ CallRuntime(Runtime::kNewFunctionContext);
-      }
+      FastNewFunctionContextStub stub(isolate());
+      __ Mov(FastNewFunctionContextDescriptor::SlotsRegister(), slots);
+      __ CallStub(&stub);
+      // Result of FastNewFunctionContextStub is always in new space.
+      need_write_barrier = false;
       if (info->scope()->new_target_var() != nullptr) {
         __ Pop(x3);  // Restore new target.
       }