innobase/btr/btr0btr.c:
  Cache the value of dtype_get_fixed_size(type) in order to avoid
  repeated calls to an external function innobase_is_mb_cset()
innobase/include/data0type.ic:
  Declare innobase_is_mb_cset().
  dtype_get_fixed_size(): Invoke innobase_is_mb_cset() for DATA_MYSQL.
innobase/row/row0ins.c:
  Cache the value of dtype_get_fixed_size(type) in order to avoid
  repeated calls to an external function innobase_is_mb_cset()
innobase/row/row0sel.c:
  row_search_for_mysql(): Added a missing rec_reget_offsets() call
  that caused an InnoDB debug assertion failure in ctype_utf8 test.
sql/ha_innodb.cc:
  Define innobase_is_mb_cset().