Starting with glibc 2.26, macros "major" and "minor" are only
available from <sys/sysmacros.h> [0]. The build fails with the
following without including this header:
Unix/FilesystemPath.cpp:84:49: error: ‘major’ was not declared in this scope
Unix/FilesystemPath.cpp:84:113: error: ‘minor’ was not declared in this scope
[0] https://sourceware.org/ml/libc-alpha/2017-02/msg00079.html
