[stubs] Introduce a dedicated FastNewObjectStub.

src/code-stubs.h

Index: src/code-stubs.h
diff --git a/src/code-stubs.h b/src/code-stubs.h
index 039b2e28f0cfd7b5901b4f5fe48da655de76bcb7..f370ce64735e994c84591d0316967d45c1cd9cd8 100644
--- a/src/code-stubs.h
+++ b/src/code-stubs.h
@@ -76,6 +76,7 @@ namespace internal {
   V(FastCloneShallowObject)                 \
   V(FastNewClosure)                         \
   V(FastNewContext)                         \
+  V(FastNewObject)                          \
   V(FastNewRestParameter)                   \
   V(FastNewSloppyArguments)                 \
   V(FastNewStrictArguments)                 \
@@ -726,6 +727,15 @@ class FastNewContextStub final : public HydrogenCodeStub {
 };
 
 
+class FastNewObjectStub final : public PlatformCodeStub {
+ public:
+  explicit FastNewObjectStub(Isolate* isolate) : PlatformCodeStub(isolate) {}
+
+  DEFINE_CALL_INTERFACE_DESCRIPTOR(FastNewObject);
+  DEFINE_PLATFORM_CODE_STUB(FastNewObject, PlatformCodeStub);
+};
+
+
 // 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