devel/cdecl: upgrade to 6.2.

Added C++11 user-defined literal support
Added support for user-defined literals. For example:

cdecl> explain int operator"" _a(unsigned long long x)
declare _a as user-defined literal (x as unsigned long long) returning int
More commands as first argument
More commands (define, namespace, set, static, typedef, and using) are now recognized as such when they are the first argument.

Added support for char8_t
Now supports C++20's char8_t.

Added support for more standard types
Added typedef declarations for div_t, imaxdiv_t, ldiv_t, lldiv_t, sig_atomic_t, streambuf, streamoff, streamsize, and wstreambuf.