[Bug target/121866] GCC unable to eliminate loop guard in some cases for riscv32

[lis8215 at gmail dot com via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121866

--- Comment #3 from Siarhei Volkau <lis8215 at gmail dot com> ---
For getting the same effect on 64-bit targets `i` and `len` must be of type
long.