Reland "Allocation site support for monomorphic StringAdds in BinaryOps".

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index a3bc56ca4306d77c8914da1ce5cc1a1a14f102e8..49916687696b4d6b05cf4caf524bc74ce7e3db25 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -3815,7 +3815,9 @@ HInstruction* HStringAdd::New(Zone* zone,
                               HValue* context,
                               HValue* left,
                               HValue* right,
-                              StringAddFlags flags) {
+                              PretenureFlag pretenure_flag,
+                              StringAddFlags flags,
+                              Handle<AllocationSite> allocation_site) {
   if (FLAG_fold_constants && left->IsConstant() && right->IsConstant()) {
     HConstant* c_right = HConstant::cast(right);
     HConstant* c_left = HConstant::cast(left);
@@ -3825,7 +3827,23 @@ HInstruction* HStringAdd::New(Zone* zone,
       return HConstant::New(zone, context, concat);
     }
   }
-  return new(zone) HStringAdd(context, left, right, flags);
+  return new(zone) HStringAdd(
+      context, left, right, pretenure_flag, flags, allocation_site);
+}
+
+
+void HStringAdd::PrintDataTo(StringStream* stream) {
+  if ((flags() & STRING_ADD_CHECK_BOTH) == STRING_ADD_CHECK_BOTH) {
+    stream->Add("_CheckBoth");
+  } else if ((flags() & STRING_ADD_CHECK_BOTH) == STRING_ADD_CHECK_LEFT) {
+    stream->Add("_CheckLeft");
+  } else if ((flags() & STRING_ADD_CHECK_BOTH) == STRING_ADD_CHECK_RIGHT) {
+    stream->Add("_CheckRight");
+  }
+  stream->Add(" (");
+  if (pretenure_flag() == NOT_TENURED) stream->Add("N");
+  else if (pretenure_flag() == TENURED) stream->Add("D");
+  stream->Add(")");
 }