Use the UAUTO SYSCTL type for exporting the bounce zone alignment,
because the variable size depends on the build type.

Reported by:	kib @
MFC after:	3 days


git-svn-id: svn+ssh://svn.freebsd.org/base/head@273423 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Mark some more sysctl stuff shared-locked and MPSAFE.


git-svn-id: svn+ssh://svn.freebsd.org/base/head@273424 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
older binutils does not know about --no-fatal-warnings


git-svn-id: svn+ssh://svn.freebsd.org/base/head@273426 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
Revert r273426 r273409

A solution that work with both new and old binutils should be investigated


git-svn-id: svn+ssh://svn.freebsd.org/base/head@273428 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f