public static BigFloat quietNaN(int fracbits, int expbits, int sign) {
		return new BigFloat(fracbits, expbits, FloatKind.QUIET_NAN, sign, BigInteger.ZERO,
			(1 << (expbits - 1)) - 1);
	}
Return the BigFloat with the given number of bits representing (quiet) NaN.

@param fracbits number of fractional bits
@param expbits number of bits in the exponent
@param sign +1 or -1
@return a BigFloat representing (quiet) NaN
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/pcode/floatformat/BigFloat.java