6598190: JPRT tests fail when run with -XX:+CheckUnhandledOops

Summary: Work around Sun Studio C++ compiler bug 6629277 in dependencies.cpp
Reviewed-by: kamg, sgoldman, pbk

src/share/vm/code/dependencies.cpp

@@ -1491,9 +1491,12 @@ bool DepChange::ContextStream::next() {
     // fall through:
     _change_type = Change_new_sub;
   case Change_new_sub:
-    _klass = instanceKlass::cast(_klass)->super();
-    if (_klass != NULL) {
-      return true;
+    // 6598190: brackets workaround Sun Studio C++ compiler bug 6629277
+    {
+      _klass = instanceKlass::cast(_klass)->super();
+      if (_klass != NULL) {
+        return true;
+      }
     }
     // else set up _ti_limit and fall through:
     _ti_limit = (_ti_base == NULL) ? 0 : _ti_base->length();