druntime\core\atomic.di(238): Error: asm statement is assumed to be @system - mark it with '@trusted' if it is not But compiling this file is OK.
Also it generated strange statements. ref rename(names...)() return if (names.length == 0 || allSatisfy!(isSomeString, typeof(names))) to ref return rename(names...)() if (names.length == 0 || allSatisfy!(isSomeString, typeof(names))) which leads to errors.
I cannot reproduce this. I just used the header generator on the latest version of druntime's core.atomic and the resulting .di file compiles successfully. There were numerous fixes for the header generator since 2016 so I assume this was fixed.