Problem:    Test failures for unreachable code.
Solution:   Add a test override to ignore unreachable code.

Problem:    USD filetype is not recognized.
Solution:   Add patterns for USD filetype. (Colin Kennedy, closes #12370)

Problem:    Some commands for opening a file don't use 'switchbuf'.
Solution:   Use 'switchbuf' for more commands. (Yegappan Lakshmanan,
            closes #12383, closes #12381)

Problem:    Typst filetype is not recognized.
Solution:   Distinguish between sql and typst. (Gaetan Lepage, closes #12363)

Problem:    Message for opening the cmdline window is not translated.
Solution:   Add gettext() and scan the defaults script for text to be
            translated.  (closes #12371)

Problem:    Global 'filetype' is set when it is detected from the file content.
Solution:   Set the local 'filetype' option value.

Problem:    Cannot use special keys in <Cmd> mapping.
Solution:   Do allow for special keys in <Cmd> and <ScriptCmd> mappings.
            (closes #12326)

Problem:    reverse() does not work for a String.
Solution:   Implement reverse() for a String. (Yegappan Lakshmanan,
            closes #12179)

Problem:    No error when calling remote_startserver() with an empty string.
Solution:   Give an error for an empty string. (Hirohito Higashi,
            closes #12327)