[Issue 12518] Add ability to not rebuild the project on file with custom build tool change

[via Digitalmars-d-bugs]

https://issues.dlang.org/show_bug.cgi?id=12518

--- Comment #2 from Rainer Schuetze <r.sagitario at gmx.de> ---
regarding 2: 0.3.39 now has a new option "assume outout uptodate with same
time" for the custom build tool.

--