Use C++ style type casts.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 8a23988de09e93fcaa5eafe0ac9a0e3e99341e04..0d1bd4305b4992b97f20fdbb7a4f53be859451f3 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -6878,7 +6878,7 @@ String* ConsStringIteratorOp::NextLeaf(bool* blew_stack,
     if ((type & kStringRepresentationMask) != kConsStringTag) {
       // Pop stack so next iteration is in correct place.
       Pop();
-      unsigned length = (unsigned) string->length();
+      unsigned length = static_cast<unsigned>(string->length());
       // Could be a flattened ConsString.
       if (length == 0) continue;
       *length_out = length;
@@ -6896,7 +6896,7 @@ String* ConsStringIteratorOp::NextLeaf(bool* blew_stack,
       type = string->map()->instance_type();
       if ((type & kStringRepresentationMask) != kConsStringTag) {
         AdjustMaximumDepth();
-        unsigned length = (unsigned) string->length();
+        unsigned length = static_cast<unsigned>(string->length());
         ASSERT(length != 0);
         *length_out = length;
         *type_out = type;