[Issue 20824] error messages generated by dmd build script can be prefixed with a non-standard "ERROR:"

[d-bugmail at puremagic.com]

https://issues.dlang.org/show_bug.cgi?id=20824

--- Comment #1 from Basile-z <b2.temp at gmx.com> ---
example

> ERROR: dmd/declaration.d(792): Error: no property `isOveDeclaration` for type `dmd.dsymbol.Dsymbol`, did you mean `dmd.dsymbol.Dsymbol.isOverDeclaration`?

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