Add runtime markers for a full-width 32x32 multiply (0x12345678 * 0x9abcdef0
= 0x242d2080) and for a wide-dividend remainder, so a 16-bit-truncated MPYS or
a wrong FS1 cannot still produce the expected small results. Compute the 16x16
unsigned product in unsigned arithmetic to remove the signed-overflow
annotation, and reject a regressed nuw nsw multiply in the optimized IR.
arti
00522b56fc