devel/cdecl: update to 6.5.

Much better alternative tokens support
Alternative tokens (and, and_eq, etc.) are now parsed correctly in all cases. Additionally, alternative tokens can be emitted via the new set alt-tokens option.

Changed -q to -p
The --quiet and -q options (that were in the original cdecl) were changed to --no-prompt and -p so they're more explicit about what they do.

Trigraphs warning
If the trigraphs option is set and the language is C++17 or later, a warning will be printed (since trigraphs were removed from C++17).

Set command output changed
The set command now only prints the current options. Its help has beed added to the help command.

Better K&R C prototypes error
The error message given when attempting to use function prototypes in K&R C has been improved.

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