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, 2 insertions, 4 deletions

diff --git a/sql/sql_insert.cc b/sql/sql_insert.cc
index 6455818993d..1745c6b4aaa 100644
--- a/sql/sql_insert.cc
+++ b/sql/sql_insert.cc
@@ -4319,14 +4319,12 @@ select_create::binlog_show_create_table(TABLE **tables, uint count)
   DBUG_ASSERT(thd->is_current_stmt_binlog_format_row());
   DBUG_ASSERT(tables && *tables && count > 0);
 
-  char buf[2048];
-  String query(buf, sizeof(buf), system_charset_info);
+  StringBuffer<2048> query(system_charset_info);
   int result;
   TABLE_LIST tmp_table_list;
 
-  memset(&tmp_table_list, 0, sizeof(tmp_table_list));
+  tmp_table_list.reset();
   tmp_table_list.table = *tables;
-  query.length(0);      // Have to zero it since constructor doesn't
 
   result= show_create_table(thd, &tmp_table_list, &query,
                             create_info, WITH_DB_NAME);