MFC r248802:

Similar to r239870 and r239872, teach the other binutils tools about the
DW_FORM_flag_present dwarf attribute, so they do not print errors or
warnings on files that contain it.  (This attribute can be emitted by
newer versions of clang and gcc.)
MFH (r246358): load pfsync.ko if necessary.
MFH (r247270, r247271): allow starting rtadvd without any interfaces.
MFH (r247810): correctly parse mixed quoted / unquoted text.
MFH (r247285): always bootstrap liby along with yacc.
MFC r248562:
Move the vn_start_write() call in the dounmount() before setting the
MNTK_UNMOUNT flag.
MFC r248563:
Increment the write ref counter for the buffer object before calling
bundirty().
MFC r248968:
Record the correct error in the trace.
MFC r248967:
Strip the unnneeded spaces, mostly at the end of lines.
MFC r248567:
Do not call vnode_pager_setsize() while a NFS node mutex is
locked. vnode_pager_setsize() might sleep waiting for the page after
EOF be unbusied.

Call vnode_pager_setsize() both for the regular and directory vnodes.

MFC r248581:
Initialize the variable to avoid (false) compiler warning about
use of an uninitialized local.
MFC r248815:
Release the v_writecount reference on the vnode in case of error,
before the vnode is vput() in vm_mmap_vnode().
MFC r247832:
Import the likely() compat macro.

MFC r247838:
Correct the r247832.
MFC r247833:
Import the drm_mm_debug_table() function.
MFC r247834:
Import the drm_global references helpers.

MFC r247839 (by dumbbell):
Destroy sx in drm_global_release().
Merge remote-tracking branch 'upstream/stable/9' into stable/9