Don't take UnkownOSRValues into account when infering Phi's representation.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 6a7b6098cb8537d747f2ce674e41e56fdd0f0c7c..013dcdce3bff2a824eaf33b02e275b29d91fe42d 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -1766,6 +1766,12 @@ void HInferRepresentation::InferBasedOnInputs(HValue* current) {
   ASSERT(current->CheckFlag(HValue::kFlexibleRepresentation));
   Representation inferred = current->InferredRepresentation();
   if (inferred.IsSpecialization()) {
+    if (FLAG_trace_representation) {
+      PrintF("Changing #%d representation %s -> %s based on inputs\n",
+             current->id(),
+             r.Mnemonic(),
+             inferred.Mnemonic());
+    }
     current->ChangeRepresentation(inferred);
     AddDependantsToWorklist(current);
   }
@@ -1793,6 +1799,12 @@ void HInferRepresentation::InferBasedOnUses(HValue* value) {
   Representation new_rep = TryChange(value);
   if (!new_rep.IsNone()) {
     if (!value->representation().Equals(new_rep)) {
+      if (FLAG_trace_representation) {
+        PrintF("Changing #%d representation %s -> %s based on uses\n",
+               value->id(),
+               r.Mnemonic(),
+               new_rep.Mnemonic());
+      }
       value->ChangeRepresentation(new_rep);
       AddDependantsToWorklist(value);
     }