Precompiled headers were put in a directory which had exactly the same
name as the binary to be generated. This resulted in a failure with any
mkspec that used clang_pch_style. The g++-mkspec avoid this problem by
extending the directory name. This change adopts this technique for
clang mkspecs.
[ChangeLog][qmake] Fixed precompiled headers for the Clang compiler.
Fixes: QTBUG-72404
Change-Id: I471462e2bcb1e33f19d277c21acde0c04b1ffcd6
Reviewed-by: BogDan Vatra <bogdan@kdab.com>
059172c633