compiling Kalles Fraktaler with GCC

[3dickulus]

https://gcc.gnu.org/onlinedocs/gcc/Decimal-Float.html
https://gcc.gnu.org/onlinedocs/gcc/Fixed-Point.html
https://gcc.gnu.org/onlinedocs/gcc/Floating-Types.html

just wondering how much of kfr's math code can use the above mentioned types and formats.

logic: if a good portion can use built-in types (quadmath integration is almost transparent) that would make the specialized code portion smaller?
         and easier to maintain while seeing benefits from gcc's type handling, format development and optimizations.