/usr/lib/mlton/include/platform/ is in mlton-basis 20130715-3.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/mlton/include/platform/aix.h
/usr/lib/mlton/include/platform/alpha.h
/usr/lib/mlton/include/platform/amd64.h
/usr/lib/mlton/include/platform/android_ucontext.h
/usr/lib/mlton/include/platform/arm.h
/usr/lib/mlton/include/platform/arm64.h
/usr/lib/mlton/include/platform/cygwin.h
/usr/lib/mlton/include/platform/darwin.h
/usr/lib/mlton/include/platform/float-math.h
/usr/lib/mlton/include/platform/freebsd.h
/usr/lib/mlton/include/platform/hppa.h
/usr/lib/mlton/include/platform/hpux.h
/usr/lib/mlton/include/platform/hurd.h
/usr/lib/mlton/include/platform/ia64.h
/usr/lib/mlton/include/platform/linux.h
/usr/lib/mlton/include/platform/m68k.h
/usr/lib/mlton/include/platform/mingw.h
/usr/lib/mlton/include/platform/mips.h
/usr/lib/mlton/include/platform/mips64.h
/usr/lib/mlton/include/platform/netbsd.h
/usr/lib/mlton/include/platform/openbsd.h
/usr/lib/mlton/include/platform/powerpc.h
/usr/lib/mlton/include/platform/powerpc64.h
/usr/lib/mlton/include/platform/s390.h
/usr/lib/mlton/include/platform/setenv.h
/usr/lib/mlton/include/platform/solaris.h
/usr/lib/mlton/include/platform/sparc.h
/usr/lib/mlton/include/platform/x86.h