Unify JSEntryStub and JSConstructEntryStub, and some more code stub cleanups.

src/x64/code-stubs-x64.cc

Index: src/x64/code-stubs-x64.cc
diff --git a/src/x64/code-stubs-x64.cc b/src/x64/code-stubs-x64.cc
index 3b3fe6286ba0e9786265a53ec82eefc9ada416e2..6e3395a225a64ab5e37dc617f698ef08679ced9a 100644
--- a/src/x64/code-stubs-x64.cc
+++ b/src/x64/code-stubs-x64.cc
@@ -2308,7 +2308,7 @@ void CEntryStub::Generate(MacroAssembler* masm) {
 }
 
 
-void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
+void JSEntryStub::GenerateBody(MacroAssembler* masm) {
   Label invoke, handler_entry, exit;
   Label not_outermost_js, not_outermost_js_2;
 
@@ -2321,7 +2321,7 @@ void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
     __ movp(rbp, rsp);
 
     // Push the stack frame type marker twice.
-    int marker = is_construct ? StackFrame::ENTRY_CONSTRUCT : StackFrame::ENTRY;
+    int marker = type_();
     // Scratch register is neither callee-save, nor an argument register on any
     // platform. It's free to use at this point.
     // Cannot use smi-register for loading yet.
@@ -2411,7 +2411,7 @@ void JSEntryStub::GenerateBody(MacroAssembler* masm, bool is_construct) {
   // external reference instead of inlining the call target address directly
   // in the code, because the builtin stubs may not have been generated yet
   // at the time this code is generated.
-  if (is_construct) {
+  if (type() == StackFrame::ENTRY_CONSTRUCT) {
     ExternalReference construct_entry(Builtins::kJSConstructEntryTrampoline,
                                       isolate());
     __ Load(rax, construct_entry);