[PATCH] Fix uninitialized data in gimple-ssa-store-merging.c (PR tree-optimization/80079)

[Marek Polacek]

Uninitialized data are never good, especially with MALLOC_PERTURB_ set in
your environment.  This patch from the PR fixes stuff for me.

Applying to trunk.

2017-03-17  Marek Polacek  <pola...@redhat.com>
            Markus Trippelsdorf  <mar...@trippelsdorf.de>

        PR tree-optimization/80079
        * gimple-ssa-store-merging.c (class pass_store_merging): Initialize
        m_stores_head.

diff --git gcc/gimple-ssa-store-merging.c gcc/gimple-ssa-store-merging.c
index 5bdb459..17a95a5 100644
--- gcc/gimple-ssa-store-merging.c
+++ gcc/gimple-ssa-store-merging.c
@@ -725,7 +725,7 @@ class pass_store_merging : public gimple_opt_pass
 {
 public:
   pass_store_merging (gcc::context *ctxt)
-    : gimple_opt_pass (pass_data_tree_store_merging, ctxt)
+    : gimple_opt_pass (pass_data_tree_store_merging, ctxt), m_stores_head ()
   {
   }
 

        Marek