Switched profiling off in the BST.
Updated NEWS.
Added some profiling code.
Fixed RTE equality predicates to work with pair structures containing
* Marked classes <class-instance>, <proc-instance>, and <raw-proc-instance>
Marked classes <factorized-expr> and <linker-instance-predef>
Optimized procedure tc-tree-il-factorized-expr.
* Optimized match-type linking in the Tree-IL BST backend.