This is Lucy Hederman's static garbage collector.  It inserts deallocation
hints into the intermediate code, and it may annotate lazy cons cells
with reference count and size information for the closure.
This is invoked only with -OO or -OOO.

A description of the techniques used can be found in ``Compile Time
Garbage Collection Using Reference Count Analysis'', Lucy Hederman,
Rice Computer Science Technical Report 88-75.

This was written in a hurry.  Some of the
data structures and coding style could be improved.  I do not
know of any bugs, other than some assumptions about the kind of intermediate
code sequences that are generated by the compiler itself.  (This appears
to assume that integer can always be ignored in the analysis.  I don't
believe this holds in general, but it probably holds for all code
generated by the compiler.  But then I may have misinterpreted the code.)

				Hans-J. Boehm (2/5/91)
