Exclude 'threading model' information from Solaris coredump tests

Exclude 'threading model' information from Solaris coredump tests

Solaris 12 transitioned to public libproc and mdb now prints
'raw lwps' instead of 'native threads' for the threading model.
This information is irrelevant for coredump generation and analysis;
therefore leave it out.
n-i-bz

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@15783