[fuzzer][wasm-gc] Fix fuzzer for array-len without type immediate

Fix for 75391be2.
The fuzzer should not generate type immediates for the new array len
opcode. As the old opcode was renamed in C++, the fuzzer switched to the
new opcode automatically.

Bug: v8:7748
Change-Id: Ife2d420e8ce5486f683f00bfff168f47745a86d2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3866171
Commit-Queue: Jakob Kummerow <jkummerow@chromium.org>
Auto-Submit: Matthias Liedtke <mliedtke@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Matthias Liedtke <mliedtke@chromium.org>
Cr-Commit-Position: refs/heads/main@{#82842}

test/fuzzer/wasm-compile.cc

@@ -1053,7 +1053,6 @@ class WasmGenerator {
       DCHECK(builder_->builder()->IsArrayType(array_index));
       GenerateRef(HeapType(array_index), data);
       builder_->EmitWithPrefix(kExprArrayLen);
-      builder_->EmitU32V(array_index);
     } else {
       Generate(kWasmI32, data);
     }