In tools/, it did not understand that some files are generated by
matchcompiler.py.
```
CMake Error at tools/CMakeLists.txt:7 (add_executable):
Cannot find source file:
</some/path>/cppcheck/build/lib/build/mc_pathmatch.cpp
Tried extensions .c .C .c++ .cc .cpp .cxx .cu .m .M .mm .h .hh .h++ .hm
.hpp .hxx .in .txx
CMake Error at tools/CMakeLists.txt:7 (add_executable):
No SOURCES given to target: dmake
```
Co-authored-by: Ken-Patrick Lehrmann <kp.lehrmann@gmail.com>