Don't ignore the actual input representation in UnaryMathOperations

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index d3f1a9e09024c8f1643eb53bddc3b595b3953d3e..751f9bfa4c8996c021616ab8f3af0262ff030020 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -3068,6 +3068,16 @@ HType HUnaryMathOperation::CalculateInferredType() {
 }
 
 
+Representation HUnaryMathOperation::RepresentationFromInputs() {
+  Representation rep = representation();
+  // If any of the actual input representation is more general than what we
+  // have so far but not Tagged, use that representation instead.
+  Representation input_rep = value()->representation();
+  if (!input_rep.IsTagged()) rep = rep.generalize(input_rep);
+  return rep;
+}
+
+
 HType HStringCharFromCode::CalculateInferredType() {
   return HType::String();
 }