GCC stdfix fixed point math support

[rma-31]

Hi, I was wondering if fixed point support for the esp32 using gcc will be added. Currently, if one tries to use this gcc feature, the compiler responds with "error: fixed-point types not supported for this target".

This would be very useful, when implementing DSP code.

Example snippet:
#include "stdfix.h"
int main(){
fract a = .33, b = .1;
a *= b;
return 0;
}