Clean up comments in sub_0200EB64 function

comments cleared

src/item_util_1.c

@@ -231,10 +231,6 @@ bool8 IsItemValidVeneer(s16 item_id)
     return IsItemValid(item_id);
 }
 
-// NOTE: the s32 return (not s16) and the explicit lsl/lsr shifts are
-// load-bearing for an exact match: s16 return emits lsl/asr #16, and
-// (idx & 1) << 4 does not produce the mov/lsl + mov/lsr pair.
-// Semantics unchanged (11-bit field, 0..0x7FF).
 s32 sub_0200EB64(s16 idx)
 {
     u32 shift = (u32)idx << 31;