Removed the auto detection and use of Solaris "libmtmalloc", as it
  cause regression on bug#18322. The code removed also prevented
  a build without using this library. Users can still compile with
  "libmtmalloc", if configuring with "--with-mysqld-libs=-lmtmalloc"


configure.in:
  Removed the auto detection and use of Solaris "libmtmalloc", as it
  cause regression on bug#18322. The code removed also prevented
  a build without using this library. Users can still compile with
  "libmtmalloc", if configuring with "--with-mysqld-libs=-lmtmalloc"