Attached is a patch that fixes this by using the following syntax-propertize-function:

(set (make-local-variable 'syntax-propertize-function)
     (syntax-propertize-rules
      ("\\(/-\\)" (1 "."))
      ("\\(-\\*\\)" (1 "."))))

Adds sql-mode syntax propertize rules to fix comment highlighting

Fixes the issue where -* and /- incorrectly starts comments
in SQL mode Bug(#35646). This is done by adding a
syntax-propertize-function to sql-mode.