Corrected some comments.

os_file_create_tmpfile(): Remove the implementation from InnoDB Hot Backup.

In InnoDB Hot Backup builds, do not define dict_casedn_str(),
which is invoked in fil_load_single_table_tablespace() on
Windows.  This function depends on innobase_casedn_str() and
my_casedn_str().

Define btr_check_node_ptr() and data_error only #ifdef UNIV_DEBUG.
They are only being used in ut_ad() assertions.

Replace the occurrences of the type uint with ulint, because InnoDB
Hot Backup does not define any uint data type.

Disable lock_validate() in InnoDB Hot Backup builds.

Disable some unused static variables of srv0srv.c in InnoDB Hot Backup builds.

Disable some srv_table_...() functions in InnoDB Hot Backup builds.

Disable some unused static variables in srv0start.c in
InnoDB Hot Backup builds.

Disable io_handler_thread() in InnoDB Hot Backup builds.

Disable srv_calc_low32() and srv_calc_high32() in InnoDB Hot Backup builds
to avoid warnings about unused functions.

In fil_node_open_file(), avoid bogus assertions in InnoDB Hot Backup builds.

In fil_load_single_table_tablespace(), remove the call to dict_casedn_str(),
as it depends on MySQL code.

Copy the code of recv_reset_log_files_for_backup() from InnoDB Hot Backup.

Disable innobase_mysql_cmp(), cmp_whole_field(), cmp_data_data_slow(),
cmp_dtuple_rec_with_match() and cmp_rec_rec_with_match()
in InnoDB Hot Backup builds, as they depend on MySQL code.

Adapt dtype_set_mblen() and dtype_get_fixed_size() for InnoDB Hot Backup
builds, assuming that they will only be called on system tables, which
do not contain multi-byte characters.

Disable the static functions row_ins_set_exclusive_rec_lock() and
row_ins_dupl_error_with_rec() in InnoDB Hot Backup builds
to avoid warnings about unused functions.

In row_sel_field_store_in_mysql_format(), disable some UTF-8 related
assertions #ifndef UNIV_RELEASE_NOT_YET_STABLE.