How to programmatically set a well-known Win32 API function pointer type?

[huettenhain]

How would I programmatically, from a Ghidra script, obtain the DataType that represents a function pointer to the CreateFileW Windows API function? The data type clearly exists, and I can use it to retype variables through the UI without any problem:

However, the getDataTypes method from the flat API does not find it, and the following code does not find it either:

DataTypeManager dtm = currentProgram.getDataTypeManager();
for (SourceArchive a : dtm.getSourceArchives()) {
	for (DataType dt : dtm.getDataTypes(a)) {
		println(dt.getName());
	}
}

I have spent quite a bit of time trying to figure out how the Ghidra UI does it, without success. Thanks a lot in advance for any help!

[huettenhain]

For a solution, see #3599!