Fix crashes due to unaligned parameters

Due to the recent introduction of isl_id, parameters need now always to be
aligned. This was not yet taken care of in the code path of vectorization and
dependence analysis.

llvm-svn: 138555
diff --git a/polly/lib/CodeGeneration.cpp b/polly/lib/CodeGeneration.cpp
index cfede95..c9c2742 100644
--- a/polly/lib/CodeGeneration.cpp
+++ b/polly/lib/CodeGeneration.cpp
@@ -1139,8 +1139,10 @@
 
     isl_set *elements = isl_map_range(sub);
 
-    if (!isl_set_is_singleton(elements))
+    if (!isl_set_is_singleton(elements)) {
+      isl_set_free(elements);
       return -1;
+    }
 
     isl_point *p = isl_set_sample_point(elements);