XSB Src (SVN)-old

Updating with some newer versions of these Mt test files.

updating these, which I apparently hadn't before the disk crash.

Adding this test, which I apparently hadn't before the disk crash.

Changes that I apparently never committed before the SourceForge disk failure.

Added new routine to be called externally, to expand heap to ensure there
is enough space for expected c2p_functor and c2p_list calls.

Add tests of retract with gc when index chains are being used.

Commit all the new .xwam files for addition of "defined" indicator
in symbol records.
Also removed a recent change to make the executable table/1 command (not
the compiler directive) imply that the predicate is dynamic. While it
doesn't make sense to call table/1 for non-dynamic, this addition
might be non-intuitive. Anyway, I took it out.

Changed compiler to set a "defined" bit in symbol table record in
the object code file to indicate that a predicate is has clauses defining
it. To enable the "table" bit to be handled correctly in usermod with
reloading (or using) of tabled predicates.
And all the .xwam files change due to this change.

Fixed loader to correctly reset (or not) tabled bit for predicate.
Required passing "defined" indication in symbol table from compiler.

Add some extern declarations to quiet compiler complaints.