The changes to the bitset macros allowed sched.h to be included
into userland programs without name space pollution due to BIT_*
and BITSET_* macros.
The definition of a "struct bitset" had been overlooked. This name
space pollution caused the build of port print/miktex to fail.
This commit makes the definition of struct bitset depend on the
same condition as the visibility of the BIT_* and BITSET_* macros,
i.e. needs _KERNEL or _WANT_FREEBSD_BITSET to be defined before
including sys/_bitset.h.
It has been tested with "make universe" since a prior attempt to
fix the issue broke the PowerPC64 kernel build.
This commit shall be MFCed together with commit 5e04571cf3c.
Reported by: arrowd
MFC after: 1 month
6af6e29552