Pretenure call new support.

src/x64/macro-assembler-x64.cc

Index: src/x64/macro-assembler-x64.cc
diff --git a/src/x64/macro-assembler-x64.cc b/src/x64/macro-assembler-x64.cc
index 1d7f541d5877f8c87f90671e69fa632fad0981b6..17e9fc4ae05a82e5b94baefe6305d5c815761562 100644
--- a/src/x64/macro-assembler-x64.cc
+++ b/src/x64/macro-assembler-x64.cc
@@ -3364,6 +3364,19 @@ void MacroAssembler::AssertName(Register object) {
 }
 
 
+void MacroAssembler::AssertUndefinedOrAllocationSite(Register object) {
+  if (emit_debug_code()) {
+    Label done_checking;
+    AssertNotSmi(object);
+    Cmp(object, isolate()->factory()->undefined_value());
+    j(equal, &done_checking);
+    Cmp(FieldOperand(object, 0), isolate()->factory()->allocation_site_map());
+    Assert(equal, kExpectedUndefinedOrCell);
+    bind(&done_checking);
+  }
+}
+
+
 void MacroAssembler::AssertRootValue(Register src,
                                      Heap::RootListIndex root_value_index,
                                      BailoutReason reason) {
@@ -4033,6 +4046,10 @@ void MacroAssembler::LoadAllocationTopHelper(Register result,
     // Assert that result actually contains top on entry.
     Operand top_operand = ExternalOperand(allocation_top);
     cmpq(result, top_operand);
+    Label fine;
+    j(equal, &fine);
+    int3();
+    bind(&fine);

[Hannes Payer (out of office), 2014/02/18 16:24:26]

I don't think this code is needed...

[mvstanton, 2014/02/19 08:40:26]

Whoa, thank you, that was me debugging somewhere in there :).

     Check(equal, kUnexpectedAllocationTop);
 #endif
     return;