Issue 9565 - Index of static array should not print literal suffix

http://d.puremagic.com/issues/show_bug.cgi?id=9565

Static array type index is always size_t, so unnecessary suffix is harmful for platform independent diagnostic message.
(Note that: In 64bit platform, size_t is ulong, and if the value is greater than `long.max`, suffix is *necessary*.)

Same problem exists in `IndexExp` and `SliceExp` printing.