Clang Static Analyzer does not find STL headers

I have an arm-none-eabi gcc toolchain.

I have successfully configured Qt Creator to use it in a Kit and was able to use it to build a QBS projects.

However, when I try to run the static analyzer, clang does not find
the standard headers (neither C++ headers nor C headers):

    main.cpp:9:10: fatal error: 'cstring' file not found

A solution is to add the include paths of the standard headers in the
QBS project:

     cpp.includePaths: [
         ".../toolchain/arm/arm-gnu-toolchain/arm-none-eabi/include/c++/6.3.1",
         ".../toolchain/arm/arm-gnu-toolchain/arm-none-eabi/include",
     ]

This issue does not occur when using the MinGW 5.3.0 toolchain installed through the Qt Online Installer.