Tagged some more arguments UNUSED

src/builtin_functions.c

src/error.c

src/gc.c

src/interpret.c

src/modules/DVB/dvb.c

src/modules/_Image_JPEG/transupp.c

src/pike_embed.c

src/post_modules/CritBit/bignumtree.cmod

src/post_modules/CritBit/critbit/key_float.h

src/post_modules/CritBit/critbit/key_int.h

src/post_modules/CritBit/tree_high.c

src/post_modules/CritBit/tree_low.c

src/post_modules/Nettle/cipher.cmod