public String getSourceFileName() {
		StringIdMsType stringIdType =
			pdb.getTypeRecord(getSourceFileNameStringIdRecordNumber(), StringIdMsType.class);
		if (stringIdType == null) {
			return null;
		}
		return stringIdType.getString();
	}
Returns the source file name.
@return the source file name.  null if problem recovering name.
Ghidra/Features/PDB/src/main/java/ghidra/app/util/bin/format/pdb2/pdbreader/type/UserDefinedTypeSourceAndLineMsType.java