libctf: do not use mmap on Solaris 11

libctf: do not use mmap on Solaris 11

Writable mmaps and read are inconsistent with each other on Solaris 11.4,
which breaks archive writing.  Simply assert that Solaris 2.11 doesn't have
mmap, falling back to read(): the archive format is being bumped shortly, to
one with completely different writeout code, so this workaround need not
stay for long.

[nca: added commit log]

libctf/
	PR libctf/29292
	* configure.ac: Turn off mmap on Solaris 2.11.
	* configure: Regenerated.