Can you get into MySQL at all ...I mean, does MySQLd start? ...if so you can just create the host table manually:
CREATE TABLE mysql.host (
Host char(60) binary NOT NULL default '',
Db char(64) binary NOT NULL default '',
Select_priv enum('N','Y') NOT NULL default 'N',
Insert_priv enum('N','Y') NOT NULL default 'N',
Update_priv enum('N','Y') NOT NULL default 'N',
Delete_priv enum('N','Y') NOT NULL default 'N',
Create_priv enum('N','Y') NOT NULL default 'N',
Drop_priv enum('N','Y') NOT NULL default 'N',
Grant_priv enum('N','Y') NOT NULL default 'N',
References_priv enum('N','Y') NOT NULL default 'N',
Index_priv enum('N','Y') NOT NULL default 'N',
Alter_priv enum('N','Y') NOT NULL default 'N',
PRIMARY KEY (Host,Db)
) TYPE=MyISAM COMMENT='Host privileges; Merged with database privileges';