use --fuel to limit loop size

Author: lum1n0us

tests/fuzz/wasm-mutator-fuzz/smith_wasm.sh

@@ -43,6 +43,7 @@ function try_generate_wasm()
 
 WASM_SHAPE=" --ensure-termination \
 --export-everything true \
+--fuel 7 \
 --generate-custom-sections true \
 --min-funcs 5 \
 --max-instructions 1024 \