Converting Unicode Escape Sequences to UTF-8

[Nordlöw via Digitalmars-d-learn]

On Thursday, 22 October 2015 at 19:13:20 UTC, Nordlöw wrote:
>> * Drop the backslash and the 'u'.
>> * Parse XXXX as a hexadecimal integer, and cast to dchar.
>> * Use std.utf.encode to convert to UTF-8. std.conv.to can 
>> probably do it
>> too, and possibly simpler, but would allocate.
>>
>> Also be aware of the longer variant with a capital U: 
>> \UXXXXXXXX (8 Xs)

Can somebody point out in which function/file DMD does this 
decoding?