Introduce SmiValuesAre31Bits and SmiValuesAre32Bits global predicate functions

src/hydrogen-instructions.cc

Index: src/hydrogen-instructions.cc
diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 997b7c2fda9b29455d03faac59c5a49a60d18d5c..26539cc2cfa624dbdaa597794a594a50a616d5f5 100644
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -2421,7 +2421,7 @@ static void PrepareConstant(Handle<Object> object) {
 
 void HConstant::Initialize(Representation r) {
   if (r.IsNone()) {
-    if (has_smi_value_ && kSmiValueSize == 31) {
+    if (has_smi_value_ && SmiValuesAre31Bits()) {
       r = Representation::Smi();
     } else if (has_int32_value_) {
       r = Representation::Integer32();