[Issue 18275] dmd deletes source file fun.cpp with `dmd fun.cpp.o main.d`

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=18275

--- Comment #4 from ArturG <var.spool.mail700 at gmail.com> ---
done https://issues.dlang.org/show_bug.cgi?id=18740

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