Fixed a few warnings.

Rev: src/docode.c:1.82
Rev: src/modules/Regexp/pike_regexp.c:1.18
Rev: src/modules/_Image_TTF/image_ttf.c:1.36
Rev: src/object.c:1.147
Rev: src/pike_memory.c:1.88
Rev: src/pike_memory.h:1.24