private static AbstractIntegerDataType[] getSignedTypes() {
		if (signedTypes == null) {
			signedTypes = new AbstractIntegerDataType[] { SignedByteDataType.dataType,
				SignedWordDataType.dataType, Integer3DataType.dataType,
				SignedDWordDataType.dataType, Integer5DataType.dataType, Integer6DataType.dataType,
				Integer7DataType.dataType, SignedQWordDataType.dataType,
				Integer16DataType.dataType };
		}
		return signedTypes;
	}
An "map" of the first 8 (by size) signed integer data types, where the element at index
<code>i</code> points to the datatype of size <code>i+1</code>, with additional types with no
size restriction appended after the first 8.

@return array of all signed integer types (char and bool types excluded)
Ghidra/Framework/SoftwareModeling/src/main/java/ghidra/program/model/data/AbstractIntegerDataType.java