SHA-3 tests fail on RISC-V with vector support enabled

[alexrp]

test-modules
+- test-std
   +- run test std-native-spacemit_x60-ReleaseSafe-libc failure
thread 1977090 panic: integer overflow
/home/ci/runner1/_layout/_work/zig/zig/lib/std/crypto/keccak_p.zig:277:22: 0x12dd7f1 in absorb (test)
            while (i + rate < bytes.len) : (i += rate) {
                     ^
/home/ci/runner1/_layout/_work/zig/zig/lib/std/crypto/sha3.zig:75:27: 0x1490043 in test.sha3-512 single (test)
            self.st.absorb(bytes);
                          ^
/home/ci/runner1/_layout/_work/zig/zig/lib/compiler/test_runner.zig:130:29: 0x11d44b7 in mainServer (test)
                test_fn.func() catch |err| switch (err) {
                            ^
/home/ci/runner1/_layout/_work/zig/zig/lib/compiler/test_runner.zig:64:26: 0x11d38d1 in main (test)
        return mainServer() catch @panic("internal test runner failure");
                         ^
../sysdeps/nptl/libc_start_call_main.h:58:16: 0x3fbac107bb in __libc_start_call_main (libc-start.c)
./csu/libc-start.c:360:3: 0x3fbac10867 in __libc_start_main_impl (libc-start.c)
error: while executing test 'crypto.sha3.test.sha3-512 single', the following command terminated with signal 6 (expected exited with code 0):
/home/ci/runner1/_layout/_work/zig/zig/zig-local-cache/o/cbf83f36db36084dc6fe7d18cdf8858f/test --cache-dir=/home/ci/runner1/_layout/_work/zig/zig/zig-local-cache --seed=0x98526171 --listen=-

Started with the LLVM 21 upgrade. Somehow LLVM's RISC-V backend seems to produce more RVV miscompilations with every release...

[alexrp]

https://codeberg.org/ziglang/zig/commit/0d4f3cc675b71dd3729c7aebab5c47b405922cee