Fix optimization difference caused by -fdump-ipa-inline

[Jan Hubicka via Gcc-patches]

Hi,
This patch fixes a bug that caused some optimizations to be dropped with
-fdump-ipa-inline.

gcc/ChangeLog:

2021-11-17  Jan Hubicka  <hubi...@ucw.cz>

        PR ipa/103246
        * ipa-modref.c (ipa_merge_modref_summary_after_inlining): Fix clearing
        of to_info_lto

diff --git a/gcc/ipa-modref.c b/gcc/ipa-modref.c
index a70575bc807..90cd1be764c 100644
--- a/gcc/ipa-modref.c
+++ b/gcc/ipa-modref.c
@@ -5123,6 +5123,7 @@ ipa_merge_modref_summary_after_inlining (cgraph_edge 
*edge)
            fprintf (dump_file, "Removed mod-ref summary for %s\n",
                     to->dump_name ());
          summaries_lto->remove (to);
+         to_info_lto = NULL;
        }
       else if (to_info_lto && dump_file)
        {
@@ -5130,7 +5131,6 @@ ipa_merge_modref_summary_after_inlining (cgraph_edge 
*edge)
            fprintf (dump_file, "Updated mod-ref summary for %s\n",
                     to->dump_name ());
          to_info_lto->dump (dump_file);
-         to_info_lto = NULL;
        }
       if (callee_info_lto)
        summaries_lto->remove (edge->callee);