* ebrowse.c: Use size_t, not int, for sizes.

* ebrowse.c: Use size_t, not int, for sizes.

This avoids a warning with gcc -Wstrict-overflow, and works
better for very large objects.
(inbuffer_size): Now size_t.  All uses changed.
(xmalloc, xrealloc, operator_name, process_file): Use size_t for
sizes.  Don't bother testing whether a size_t value can be negative.