Rule 17.3 : pointer arithmetic

These are typically used when pointer arithmetic is required.

./src/alloc.c
./src/buffer_io.c
./src/char_io.c
./src/direct_io.c
./src/file_pos.c
./src/printformat.c
./src/string.c
./src/strtold.c
./src/sun_math/ansi_fp.c
./src/time.c
./src/wcstold.c
./src/wprintf.c
./src/wprintformat.c
./src/wscanf.c
./src/wstring.c
./src/wtime.c