The c/c++ parser does not work if libclang-common-5.0-dev is not installed.

STEPS TO REPRODUCE
1. make sure libclang-common-5.0-dev is not installed
2. install kdevelop
3. open a project

OBSERVED RESULT
code is not parse correctly
following text is printed out:
kdevplatform.shell: Could not load plugin "kdevclangsupport" , it reported the error: "The clang builtin include path \"/usr/lib/llvm-5.0/lib/clang/5.0.1/include\" is invalid (missing cpuid.h header).\nTry setting the KDEV_CLANG_BUILTIN_DIR environment variable manually to fix this.\nSee also: https://bugs.kde.org/show_bug.cgi?id=393779" Disabling the plugin now.

EXPECTED RESULT
code is parsed correctly

ADDITIONAL INFORMATION
see also above mention bug #393779

once libclang-common-5.0-dev is installed, everything works as expected