protected void makeSignalingNaN() {
		this.kind = FloatKind.SIGNALING_NAN;
	}
If finite, the returned BigDecimal is exactly equal to this.  If not finite, one of the
FloatFormat.BIG_* constants is returned.

@return a BigDecimal or null if value is NaN (i.e., {@link FloatKind#QUIET_NAN} or 
{@link FloatKind#SIGNALING_NAN}).
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/pcode/floatformat/BigFloat.java