Fix invalid debug code assertion on x64.

R=hpayer@chromium.org

Review URL: https://codereview.chromium.org/131323003

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@18514 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/x64/code-stubs-x64.cc

@@ -4274,7 +4274,7 @@ void BinaryOpICWithAllocationSiteStub::Generate(MacroAssembler* masm) {
   // Make sure that we actually patched the allocation site.
   if (FLAG_debug_code) {
     __ testb(rcx, Immediate(kSmiTagMask));
-    __ Assert(zero, kExpectedAllocationSite);
+    __ Assert(not_equal, kExpectedAllocationSite);
     __ Cmp(FieldOperand(rcx, HeapObject::kMapOffset),
            isolate->factory()->allocation_site_map());
     __ Assert(equal, kExpectedAllocationSite);