public FunctionDefinition getFunctionSignature(DIEAggregate diea) {
		diea = getFuncDIEA(diea);
		if (diea != null) {
			DWARFName dni = prog.getName(diea);
			return createFunctionDefinitionDataType(diea, dni);
		}
		return null;
	}
Construct a temporary 'impl' {@link FunctionDefinition} DataType using the information
found in the specified {@link DIEAggregate}.

@param diea {@link DIEAggregate} of a subprogram, callsite, etc.
@return {@link FunctionDefinition} impl (not saved to the DB) or null if not a valid
DIEA.
Ghidra/Features/Base/src/main/java/ghidra/app/util/bin/format/dwarf/DWARFDataTypeManager.java