fix gcc 8 compiler warnings

There were two newly enabled warnings:
1. cast for a function pointers. Affected sql_analyse.h, mi_write.c
   and ma_write.cc, mf_iocache-t.cc, mysqlbinlog.cc, encryption.cc, etc

2. memcpy/memset of nontrivial structures. Fixed as:
* the warning disabled for InnoDB
* TABLE, TABLE_SHARE, and TABLE_LIST got a new method reset() which
  does the bzero(), which is safe for these classes, but any other
  bzero() will still cause a warning
* Table_scope_and_contents_source_st uses `TABLE_LIST *` (trivial)
  instead of `SQL_I_List<TABLE_LIST>` (not trivial) so it's safe to
  bzero now.
* added casts in debug_sync.cc and sql_select.cc (for JOIN)
* move assignment method for MDL_request instead of memcpy()
* PARTIAL_INDEX_INTERSECT_INFO::init() instead of bzero()
* remove constructor from READ_RECORD() to make it trivial
* replace some memcpy() with c++ copy assignments

1 files changed, 5 insertions, 6 deletions

diff --git a/sql/partition_info.cc b/sql/partition_info.cc
index c633ea708d0..892b7e8bd05 100644
--- a/sql/partition_info.cc
+++ b/sql/partition_info.cc
@@ -47,7 +47,7 @@ partition_info *partition_info::get_clone(THD *thd)
     mem_alloc_error(sizeof(partition_info));
     DBUG_RETURN(NULL);
   }
-  memcpy(clone, this, sizeof(partition_info));
+  *clone= *this;
   memset(&(clone->read_partitions), 0, sizeof(clone->read_partitions));
   memset(&(clone->lock_partitions), 0, sizeof(clone->lock_partitions));
   clone->bitmaps_are_initialized= FALSE;
@@ -63,7 +63,7 @@ partition_info *partition_info::get_clone(THD *thd)
       mem_alloc_error(sizeof(partition_element));
       DBUG_RETURN(NULL);
     }
-    memcpy(part_clone, part, sizeof(partition_element));
+    *part_clone= *part;
     part_clone->subpartitions.empty();
     while ((subpart= (subpart_it++)))
     {
@@ -73,7 +73,7 @@ partition_info *partition_info::get_clone(THD *thd)
         mem_alloc_error(sizeof(partition_element));
         DBUG_RETURN(NULL);
       }
-      memcpy(subpart_clone, subpart, sizeof(partition_element));
+      *subpart_clone= *subpart;
       part_clone->subpartitions.push_back(subpart_clone, mem_root);
     }
     clone->partitions.push_back(part_clone, mem_root);
@@ -1897,12 +1897,11 @@ void partition_info::print_no_partition_found(TABLE *table_arg, myf errflag)
   TABLE_LIST table_list;
   THD *thd= current_thd;
 
-  bzero(&table_list, sizeof(table_list));
+  table_list.reset();
   table_list.db= table_arg->s->db.str;
   table_list.table_name= table_arg->s->table_name.str;
 
-  if (check_single_table_access(thd,
-                                SELECT_ACL, &table_list, TRUE))
+  if (check_single_table_access(thd, SELECT_ACL, &table_list, TRUE))
   {
     my_message(ER_NO_PARTITION_FOR_GIVEN_VALUE,
                ER_THD(thd, ER_NO_PARTITION_FOR_GIVEN_VALUE_SILENT), errflag);