Problem:    Error number used twice.
Solution:   Renumber of of the errors.

Problem:    MS-Windows: using type casts for timer IDs.
Solution:   Remove type casts and use the right type. (Ken Takata,
            closes #9690)  Remove old debug comments.  Rename variables and
            functions.

Problem:    Warnings reported by MSVC.
Solution:   Rename variables and other fixes. (Ken Takata, closes #9689)

Problem:    Preprocessor indents are inconsistent.
Solution:   Fix preprocessor indents. (Ken Takata, closes #9691)

Problem:    Cannot assign empty list with any list type to variable with
            specific list type.
Solution:   Use unknown list type for empty list if the specified type is any.

Problem:    Vim9: strict type checking after copy() and deepcopy().
Solution:   Allow type to change after making a copy. (closes #9644)

Problem:    Vim9: type of item in for loop not checked properly.
Solution:   Adjust the type checking. (closes #9683)

Problem:    Old mac resources files are no longer used.
Solution:   Delete the unused files. (Ozaki Kiichi, closes #9688)

Problem:    Using a variable for the return value is not needed.
Solution:   Return the value directly. (closes #9687)

Problem:    Restricted mode requires the -Z command line option.
Solution:   Use restricted mode when $SHELL ends in "nologin" or "false".
            (closes #9681)