Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

MFC r236355:
Fix a variety of compile errors with gcc48 and clang

PR: bin/165699
Approved by: cperciva (implicit)

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

sysctlbyname() returns -1 on error and sets errno. It does
not return the error itself.

The sequence number is now a node under which the MCA records are
hung by CPU id.
When showing the MCA record, print the MIB as a comment.

PR: ia64/113102

o Replace 'struct uuid' with 'uuid_t',
o Replace memcmp with uuid_equal(3),
o Use uuid_to_string(3) to convert to UUIds to string.

Do not emit values as var=value while everything else looks like
XML. Emit the values as <var>value</var> for consistency.

Grab a snapshot of Marcel's WIP ia64 machine check decoder.

Obtained from: marcel