Fix compile warnings on windows

The fix needs a followup: "ulong" is 32-bit on 64-bit Windows, so
xpand_connection_cursor::rowdata::length needs to be 64-bit but
this causes a cascade of datatype changes all over the code.

storage/xpand/ha_xpand.cc

@@ -945,7 +945,7 @@ int ha_xpand::index_read(uchar * buf, const uchar * key, uint key_len,
   uchar *rowdata = NULL;
   if (exact) {
     is_scan = false;
-    ulong rowdata_length;
+    ulonglong rowdata_length;
     error_code = trx->key_read(xpand_table_oid, 0, xpd_lock_type,
                                table->read_set, packed_key, packed_key_len,
                                &rowdata, &rowdata_length);
@@ -1170,7 +1170,7 @@ int ha_xpand::rnd_pos(uchar * buf, uchar *pos)
   build_key_packed_row(table->s->primary_key, buf, packed_key, &packed_key_len);
 
   uchar *rowdata = NULL;
-  ulong rowdata_length;
+  ulonglong rowdata_length;
   if ((error_code = trx->key_read(xpand_table_oid, 0, xpd_lock_type,
                                   table->read_set, packed_key, packed_key_len,
                                   &rowdata, &rowdata_length)))

storage/xpand/xpand_connection.cc

@@ -528,7 +528,7 @@ int xpand_connection::key_delete(ulonglong xpand_table_oid,
 int xpand_connection::key_read(ulonglong xpand_table_oid, uint index,
                                xpand_lock_mode_t lock_mode, MY_BITMAP *read_set,
                                uchar *packed_key, ulong packed_key_length,
-                               uchar **rowdata, ulong *rowdata_length)
+                               uchar **rowdata, ulonglong *rowdata_length)
 {
   int error_code;
   command_length = 0;
@@ -625,7 +625,7 @@ class xpand_connection_cursor {
     }
 
     uchar *rowdata = xpand_net->net.read_pos;
-    ulong rowdata_length = safe_net_field_length_ll(&rowdata, packet_length);
+    ulong rowdata_length = (ulong) safe_net_field_length_ll(&rowdata, packet_length);
     if (!rowdata_length) {
       // We have read all rows in this batch.
       DBUG_RETURN(0);

storage/xpand/xpand_connection.h

@@ -78,7 +78,7 @@ class xpand_connection
   int key_read(ulonglong xpand_table_oid, uint index,
                xpand_lock_mode_t lock_mode, MY_BITMAP *read_set,
                uchar *packed_key, ulong packed_key_length, uchar **rowdata,
-               ulong *rowdata_length);
+               ulonglong *rowdata_length);
   enum sort_order {SORT_NONE = 0, SORT_ASC = 1, SORT_DESC = 2};
   enum scan_type {
     READ_KEY_OR_NEXT,  /* rows with key and greater */