Fix validation check for shuffle immediates

Off-by-one error - valid shuffle values are [0..31] (inclusive).

Bug: chromium:1092013
Change-Id: Ic9edd79acb148fd2061869a1765b9a50e38403ae
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2239754Reviewed-by: Deepti Gandluri <gdeepti@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68307}

src/wasm/function-body-decoder-impl.h

@@ -1294,7 +1294,7 @@ class WasmDecoder : public Decoder {
       max_lane = std::max(max_lane, imm.shuffle[i]);
     }
     // Shuffle indices must be in [0..31] for a 16 lane shuffle.
-    if (!VALIDATE(max_lane <= 2 * kSimd128Size)) {
+    if (!VALIDATE(max_lane < 2 * kSimd128Size)) {
       error(pc_ + 2, "invalid shuffle mask");
       return false;
     }