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, 11 insertions, 4 deletions

diff --git a/sql/encryption.cc b/sql/encryption.cc
index 52eab262570..e5b54633066 100644
--- a/sql/encryption.cc
+++ b/sql/encryption.cc
@@ -25,6 +25,10 @@ struct encryption_service_st encryption_handler;
 
 extern "C" {
 
+uint no_get_key(uint, uint, uchar*, uint*)
+{
+  return ENCRYPTION_KEY_VERSION_INVALID;
+}
 uint no_key(uint)
 {
   return ENCRYPTION_KEY_VERSION_INVALID;
@@ -47,6 +51,11 @@ static unsigned int get_length(unsigned int slen, unsigned int key_id,
   return my_aes_get_size(MY_AES_CBC, slen);
 }
 
+uint ctx_size(unsigned int, unsigned int)
+{
+  return MY_AES_CTX_SIZE;
+}
+
 } /* extern "C" */
 
 int initialize_encryption_plugin(st_plugin_int *plugin)
@@ -72,8 +81,7 @@ int initialize_encryption_plugin(st_plugin_int *plugin)
   if (handle->crypt_ctx_size)
     encryption_handler.encryption_ctx_size_func= handle->crypt_ctx_size;
   else
-    encryption_handler.encryption_ctx_size_func=
-      (uint (*)(unsigned int, unsigned int))my_aes_ctx_size;
+    encryption_handler.encryption_ctx_size_func= ctx_size;
 
   encryption_handler.encryption_ctx_init_func=
     handle->crypt_ctx_init ? handle->crypt_ctx_init : ctx_init;
@@ -102,8 +110,7 @@ int finalize_encryption_plugin(st_plugin_int *plugin)
 
   if (used)
   {
-    encryption_handler.encryption_key_get_func=
-        (uint (*)(uint, uint, uchar*, uint*))no_key;
+    encryption_handler.encryption_key_get_func= no_get_key;
     encryption_handler.encryption_key_get_latest_version_func= no_key;
     encryption_handler.encryption_ctx_size_func= zero_size;
   }